foo.cc:1:12: error: stray '#' in program
    1 | stO %%% Orz#pragma GCC optimize ("Ofast")
      |            ^
foo.cc:1:1: error: 'stO' does not name a type; did you mean 'std'?
    1 | stO %%% Orz#pragma GCC optimize ("Ofast")
      | ^~~
      | std
In file included from /usr/include/c++/9/cmath:43,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/include/c++/9/ext/type_traits.h:162:35: error: 'bool __gnu_cxx::__is_null_pointer' redeclared as different kind of entity
  162 |   __is_null_pointer(std::nullptr_t)
      |                                   ^
/usr/include/c++/9/ext/type_traits.h:157:5: note: previous declaration 'template<class _Type> bool __gnu_cxx::__is_null_pointer(_Type)'
  157 |     __is_null_pointer(_Type)
      |     ^~~~~~~~~~~~~~~~~
/usr/include/c++/9/ext/type_traits.h:162:26: error: 'nullptr_t' is not a member of 'std'
  162 |   __is_null_pointer(std::nullptr_t)
      |                          ^~~~~~~~~
In file included from /usr/include/c++/9/bits/exception_ptr.h:40,
                 from /usr/include/c++/9/exception:143,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/new:125:50: error: declaration of 'operator new' as non-function
  125 | _GLIBCXX_NODISCARD void* operator new(std::size_t) _GLIBCXX_THROW (std::bad_alloc)
      |                                                  ^
/usr/include/c++/9/new:125:44: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  125 | _GLIBCXX_NODISCARD void* operator new(std::size_t) _GLIBCXX_THROW (std::bad_alloc)
      |                                            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/exception_ptr.h:40,
                 from /usr/include/c++/9/exception:143,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/new:126:41: error: attributes after parenthesized initializer ignored [-fpermissive]
  126 |   __attribute__((__externally_visible__));
      |                                         ^
/usr/include/c++/9/new:127:52: error: declaration of 'operator new []' as non-function
  127 | _GLIBCXX_NODISCARD void* operator new[](std::size_t) _GLIBCXX_THROW (std::bad_alloc)
      |                                                    ^
/usr/include/c++/9/new:127:46: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  127 | _GLIBCXX_NODISCARD void* operator new[](std::size_t) _GLIBCXX_THROW (std::bad_alloc)
      |                                              ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/exception_ptr.h:40,
                 from /usr/include/c++/9/exception:143,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/new:128:41: error: attributes after parenthesized initializer ignored [-fpermissive]
  128 |   __attribute__((__externally_visible__));
      |                                         ^
/usr/include/c++/9/new:139:44: error: declaration of 'operator new' as non-function
  139 | _GLIBCXX_NODISCARD void* operator new(std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
      |                                            ^~~~~~
/usr/include/c++/9/new:139:44: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/exception_ptr.h:40,
                 from /usr/include/c++/9/exception:143,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/new:139:52: error: expected primary-expression before 'const'
  139 | _GLIBCXX_NODISCARD void* operator new(std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
      |                                                    ^~~~~
/usr/include/c++/9/new:141:46: error: declaration of 'operator new []' as non-function
  141 | _GLIBCXX_NODISCARD void* operator new[](std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
      |                                              ^~~~~~
/usr/include/c++/9/new:141:46: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/exception_ptr.h:40,
                 from /usr/include/c++/9/exception:143,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/new:141:54: error: expected primary-expression before 'const'
  141 | _GLIBCXX_NODISCARD void* operator new[](std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
      |                                                      ^~~~~
/usr/include/c++/9/new:173:51: error: declaration of 'operator new' as non-function
  173 | _GLIBCXX_NODISCARD inline void* operator new(std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT
      |                                                   ^~~~~~
/usr/include/c++/9/new:173:51: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/exception_ptr.h:40,
                 from /usr/include/c++/9/exception:143,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/new:173:59: error: expected primary-expression before 'void'
  173 | _GLIBCXX_NODISCARD inline void* operator new(std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT
      |                                                           ^~~~
/usr/include/c++/9/new:175:53: error: declaration of 'operator new []' as non-function
  175 | _GLIBCXX_NODISCARD inline void* operator new[](std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT
      |                                                     ^~~~~~
/usr/include/c++/9/new:175:53: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/exception_ptr.h:40,
                 from /usr/include/c++/9/exception:143,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/new:175:61: error: expected primary-expression before 'void'
  175 | _GLIBCXX_NODISCARD inline void* operator new[](std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT
      |                                                             ^~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:361:31: error: 'std::size_t' has not been declared
  361 |   template<typename _Tp, std::size_t _Size>
      |                               ^~~~~~
/usr/include/c++/9/type_traits:362:25: error: '_Size' was not declared in this scope
  362 |     struct is_array<_Tp[_Size]>
      |                         ^~~~~
/usr/include/c++/9/type_traits:362:31: error: template argument 1 is invalid
  362 |     struct is_array<_Tp[_Size]>
      |                               ^
/usr/include/c++/9/type_traits:560:42: error: 'nullptr_t' is not a member of 'std'; did you mean 'nullptr_t'?
  560 |     struct __is_null_pointer_helper<std::nullptr_t>
      |                                          ^~~~~~~~~
In file included from /usr/include/c++/9/cstddef:50,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:45,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:433:29: note: 'nullptr_t' declared here
  433 |   typedef decltype(nullptr) nullptr_t;
      |                             ^~~~~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:560:42: error: 'nullptr_t' is not a member of 'std'; did you mean 'nullptr_t'?
  560 |     struct __is_null_pointer_helper<std::nullptr_t>
      |                                          ^~~~~~~~~
In file included from /usr/include/c++/9/cstddef:50,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:45,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:433:29: note: 'nullptr_t' declared here
  433 |   typedef decltype(nullptr) nullptr_t;
      |                             ^~~~~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:560:51: error: template argument 1 is invalid
  560 |     struct __is_null_pointer_helper<std::nullptr_t>
      |                                                   ^
/usr/include/c++/9/type_traits:1246:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1246 |     : public integral_constant<std::size_t, alignof(_Tp)> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:1246:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1246 |     : public integral_constant<std::size_t, alignof(_Tp)> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:1246:57: error: template argument 1 is invalid
 1246 |     : public integral_constant<std::size_t, alignof(_Tp)> { };
      |                                                         ^
/usr/include/c++/9/type_traits:1246:57: note: invalid template non-type parameter
/usr/include/c++/9/type_traits:1251:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1251 |     : public integral_constant<std::size_t, 0> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:1251:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1251 |     : public integral_constant<std::size_t, 0> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:1251:46: error: template argument 1 is invalid
 1251 |     : public integral_constant<std::size_t, 0> { };
      |                                              ^
/usr/include/c++/9/type_traits:1251:46: note: invalid template non-type parameter
/usr/include/c++/9/type_traits:1253:31: error: 'std::size_t' has not been declared
 1253 |   template<typename _Tp, std::size_t _Size>
      |                               ^~~~~~
/usr/include/c++/9/type_traits:1254:21: error: '_Size' was not declared in this scope
 1254 |     struct rank<_Tp[_Size]>
      |                     ^~~~~
/usr/include/c++/9/type_traits:1254:27: error: template argument 1 is invalid
 1254 |     struct rank<_Tp[_Size]>
      |                           ^
/usr/include/c++/9/type_traits:1255:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1255 |     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:1255:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1255 |     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:1255:65: error: template argument 1 is invalid
 1255 |     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
      |                                                                 ^
/usr/include/c++/9/type_traits:1255:65: note: invalid template non-type parameter
/usr/include/c++/9/type_traits:1259:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1259 |     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:1259:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1259 |     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:1259:65: error: template argument 1 is invalid
 1259 |     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
      |                                                                 ^
/usr/include/c++/9/type_traits:1259:65: note: invalid template non-type parameter
/usr/include/c++/9/type_traits:1264:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1264 |     : public integral_constant<std::size_t, 0> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:1264:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1264 |     : public integral_constant<std::size_t, 0> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:1264:46: error: template argument 1 is invalid
 1264 |     : public integral_constant<std::size_t, 0> { };
      |                                              ^
/usr/include/c++/9/type_traits:1264:46: note: invalid template non-type parameter
/usr/include/c++/9/type_traits:1266:47: error: 'std::size_t' has not been declared
 1266 |   template<typename _Tp, unsigned _Uint, std::size_t _Size>
      |                                               ^~~~~~
/usr/include/c++/9/type_traits:1267:23: error: '_Size' was not declared in this scope
 1267 |     struct extent<_Tp[_Size], _Uint>
      |                       ^~~~~
/usr/include/c++/9/type_traits:1267:36: error: template argument 1 is invalid
 1267 |     struct extent<_Tp[_Size], _Uint>
      |                                    ^
/usr/include/c++/9/type_traits:1268:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1268 |     : public integral_constant<std::size_t,
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:1268:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1268 |     : public integral_constant<std::size_t,
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:1269:24: error: '_Size' was not declared in this scope
 1269 |           _Uint == 0 ? _Size : extent<_Tp,
      |                        ^~~~~
/usr/include/c++/9/type_traits:1270:28: error: template argument 1 is invalid
 1270 |           _Uint - 1>::value>
      |                            ^
/usr/include/c++/9/type_traits:1270:28: note: invalid template non-type parameter
/usr/include/c++/9/type_traits:1275:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1275 |     : public integral_constant<std::size_t,
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:1275:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1275 |     : public integral_constant<std::size_t,
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/move.h:55,
                 from /usr/include/c++/9/bits/nested_exception.h:40,
                 from /usr/include/c++/9/exception:144,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/type_traits:1277:31: error: template argument 1 is invalid
 1277 |              _Uint - 1>::value>
      |                               ^
/usr/include/c++/9/type_traits:1277:31: note: invalid template non-type parameter
/usr/include/c++/9/type_traits:1832:31: error: 'std::size_t' has not been declared
 1832 |   template<typename _Tp, std::size_t _Size>
      |                               ^~~~~~
/usr/include/c++/9/type_traits:1833:30: error: '_Size' was not declared in this scope
 1833 |     struct remove_extent<_Tp[_Size]>
      |                              ^~~~~
/usr/include/c++/9/type_traits:1833:36: error: template argument 1 is invalid
 1833 |     struct remove_extent<_Tp[_Size]>
      |                                    ^
/usr/include/c++/9/type_traits:1845:31: error: 'std::size_t' has not been declared
 1845 |   template<typename _Tp, std::size_t _Size>
      |                               ^~~~~~
/usr/include/c++/9/type_traits:1846:35: error: '_Size' was not declared in this scope
 1846 |     struct remove_all_extents<_Tp[_Size]>
      |                                   ^~~~~
/usr/include/c++/9/type_traits:1846:41: error: template argument 1 is invalid
 1846 |     struct remove_all_extents<_Tp[_Size]>
      |                                         ^
/usr/include/c++/9/type_traits:1904:17: error: 'std::size_t' has not been declared
 1904 |   template<std::size_t _Len>
      |                 ^~~~~~
/usr/include/c++/9/type_traits:1909:23: error: '_Len' was not declared in this scope
 1909 |  unsigned char __data[_Len];
      |                       ^~~~
/usr/include/c++/9/type_traits:1924:17: error: 'std::size_t' has not been declared
 1924 |   template<std::size_t _Len, std::size_t _Align =
      |                 ^~~~~~
/usr/include/c++/9/type_traits:1924:35: error: 'std::size_t' has not been declared
 1924 |   template<std::size_t _Len, std::size_t _Align =
      |                                   ^~~~~~
/usr/include/c++/9/type_traits:1925:48: error: '_Len' was not declared in this scope
 1925 |     __alignof__(typename __aligned_storage_msa<_Len>::__type)>
      |                                                ^~~~
/usr/include/c++/9/type_traits:1925:52: error: template argument 1 is invalid
 1925 |     __alignof__(typename __aligned_storage_msa<_Len>::__type)>
      |                                                    ^
/usr/include/c++/9/type_traits:1930:23: error: '_Len' was not declared in this scope
 1930 |  unsigned char __data[_Len];
      |                       ^~~~
/usr/include/c++/9/type_traits:1931:37: error: '_Align' was not declared in this scope
 1931 |  struct __attribute__((__aligned__((_Align)))) { } __align;
      |                                     ^~~~~~
In file included from /usr/include/c++/9/bits/stl_algobase.h:64,
                 from /usr/include/c++/9/bits/char_traits.h:39,
                 from /usr/include/c++/9/ios:40,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/stl_pair.h:86:17: error: 'std::size_t' has not been declared
   86 |   template<std::size_t...>
      |                 ^~~~~~
/usr/include/c++/9/bits/stl_pair.h:434:41: error: 'std::size_t' has not been declared
  434 |       template<typename... _Args1, std::size_t... _Indexes1,
      |                                         ^~~~~~
/usr/include/c++/9/bits/stl_pair.h:435:41: error: 'std::size_t' has not been declared
  435 |                typename... _Args2, std::size_t... _Indexes2>
      |                                         ^~~~~~
/usr/include/c++/9/bits/stl_pair.h:437:27: error: '_Indexes1' was not declared in this scope
  437 |              _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>);
      |                           ^~~~~~~~~
/usr/include/c++/9/bits/stl_pair.h:437:36: error: expected parameter pack before '...'
  437 |              _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>);
      |                                    ^~~
/usr/include/c++/9/bits/stl_pair.h:437:39: error: template argument 1 is invalid
  437 |              _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>);
      |                                       ^
/usr/include/c++/9/bits/stl_pair.h:437:55: error: '_Indexes2' was not declared in this scope
  437 |              _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>);
      |                                                       ^~~~~~~~~
/usr/include/c++/9/bits/stl_pair.h:437:64: error: expected parameter pack before '...'
  437 |              _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>);
      |                                                                ^~~
/usr/include/c++/9/bits/stl_pair.h:437:67: error: template argument 1 is invalid
  437 |              _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>);
      |                                                                   ^
In file included from /usr/include/c++/9/ios:40,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/char_traits.h:108:66: error: 'std::size_t' has not been declared
  108 |       compare(const char_type* __s1, const char_type* __s2, std::size_t __n);
      |                                                                  ^~~~~~
/usr/include/c++/9/bits/char_traits.h:110:40: error: 'size_t' in namespace 'std' does not name a type
  110 |       static _GLIBCXX14_CONSTEXPR std::size_t
      |                                        ^~~~~~
/usr/include/c++/9/bits/char_traits.h:114:39: error: 'std::size_t' has not been declared
  114 |       find(const char_type* __s, std::size_t __n, const char_type& __a);
      |                                       ^~~~~~
/usr/include/c++/9/bits/char_traits.h:117:57: error: 'std::size_t' has not been declared
  117 |       move(char_type* __s1, const char_type* __s2, std::size_t __n);
      |                                                         ^~~~~~
/usr/include/c++/9/bits/char_traits.h:120:57: error: 'std::size_t' has not been declared
  120 |       copy(char_type* __s1, const char_type* __s2, std::size_t __n);
      |                                                         ^~~~~~
/usr/include/c++/9/bits/char_traits.h:123:35: error: 'std::size_t' has not been declared
  123 |       assign(char_type* __s, std::size_t __n, char_type __a);
      |                                   ^~~~~~
/usr/include/c++/9/bits/char_traits.h:149:64: error: 'std::size_t' has not been declared
  149 |     compare(const char_type* __s1, const char_type* __s2, std::size_t __n)
      |                                                                ^~~~~~
/usr/include/c++/9/bits/char_traits.h: In static member function 'static int __gnu_cxx::char_traits<_CharT>::compare(const char_type*, const char_type*, int)':
/usr/include/c++/9/bits/char_traits.h:151:17: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  151 |       for (std::size_t __i = 0; __i < __n; ++__i)
      |                 ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/ios:40,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/char_traits.h:151:33: error: '__i' was not declared in this scope; did you mean '__n'?
  151 |       for (std::size_t __i = 0; __i < __n; ++__i)
      |                                 ^~~
      |                                 __n
/usr/include/c++/9/bits/char_traits.h: At global scope:
/usr/include/c++/9/bits/char_traits.h:160:31: error: 'size_t' in namespace 'std' does not name a type
  160 |     _GLIBCXX14_CONSTEXPR std::size_t
      |                               ^~~~~~
/usr/include/c++/9/bits/char_traits.h:173:37: error: 'std::size_t' has not been declared
  173 |     find(const char_type* __s, std::size_t __n, const char_type& __a)
      |                                     ^~~~~~
/usr/include/c++/9/bits/char_traits.h: In static member function 'static const char_type* __gnu_cxx::char_traits<_CharT>::find(const char_type*, int, const char_type&)':
/usr/include/c++/9/bits/char_traits.h:175:17: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  175 |       for (std::size_t __i = 0; __i < __n; ++__i)
      |                 ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/ios:40,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/char_traits.h:175:33: error: '__i' was not declared in this scope; did you mean '__s'?
  175 |       for (std::size_t __i = 0; __i < __n; ++__i)
      |                                 ^~~
      |                                 __s
/usr/include/c++/9/bits/char_traits.h: At global scope:
/usr/include/c++/9/bits/char_traits.h:184:55: error: 'std::size_t' has not been declared
  184 |     move(char_type* __s1, const char_type* __s2, std::size_t __n)
      |                                                       ^~~~~~
/usr/include/c++/9/bits/char_traits.h:195:55: error: 'std::size_t' has not been declared
  195 |     copy(char_type* __s1, const char_type* __s2, std::size_t __n)
      |                                                       ^~~~~~
/usr/include/c++/9/bits/char_traits.h:205:33: error: 'std::size_t' has not been declared
  205 |     assign(char_type* __s, std::size_t __n, char_type __a)
      |                                 ^~~~~~
In file included from /usr/include/x86_64-linux-gnu/c++/9/bits/c++allocator.h:33,
                 from /usr/include/c++/9/bits/allocator.h:46,
                 from /usr/include/c++/9/string:41,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/new_allocator.h:44:14: error: 'std::size_t' has not been declared
   44 |   using std::size_t;
      |              ^~~~~~
/usr/include/c++/9/ext/new_allocator.h:45:14: error: 'std::ptrdiff_t' has not been declared
   45 |   using std::ptrdiff_t;
      |              ^~~~~~~~~
In file included from /usr/include/c++/9/ext/alloc_traits.h:36,
                 from /usr/include/c++/9/bits/basic_string.h:40,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/alloc_traits.h:411:36: error: 'ptrdiff_t' in namespace 'std' does not name a type
  411 |       using difference_type = std::ptrdiff_t;
      |                                    ^~~~~~~~~
/usr/include/c++/9/bits/alloc_traits.h:414:30: error: 'size_t' in namespace 'std' does not name a type
  414 |       using size_type = std::size_t;
      |                              ^~~~~~
/usr/include/c++/9/bits/alloc_traits.h:442:37: error: 'size_type' has not been declared
  442 |       allocate(allocator_type& __a, size_type __n)
      |                                     ^~~~~~~~~
/usr/include/c++/9/bits/alloc_traits.h:456:37: error: 'size_type' has not been declared
  456 |       allocate(allocator_type& __a, size_type __n, const_void_pointer __hint)
      |                                     ^~~~~~~~~
/usr/include/c++/9/bits/alloc_traits.h:468:52: error: 'size_type' has not been declared
  468 |       deallocate(allocator_type& __a, pointer __p, size_type __n)
      |                                                    ^~~~~~~~~
/usr/include/c++/9/bits/alloc_traits.h:503:14: error: 'size_type' does not name a type; did you mean 'true_type'?
  503 |       static size_type
      |              ^~~~~~~~~
      |              true_type
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:55:51: error: 'std::size_t' has not been declared
   55 |     const char* __name, const _CharT* __str, std::size_t* __idx,
      |                                                   ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:48: error: 'std::size_t' has not been declared
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |                                                ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:100:31: error: 'std::size_t' has not been declared
  100 |      __builtin_va_list), std::size_t __n,
      |                               ^~~~~~
In file included from /usr/include/c++/9/bits/basic_string.h:40,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/alloc_traits.h: In instantiation of 'struct __gnu_cxx::__alloc_traits<std::allocator<char>, char>':
/usr/include/c++/9/bits/basic_string.h:84:24:   required from 'class std::__cxx11::basic_string<char>'
/usr/include/c++/9/bits/basic_string.h:6507:68:   required from here
/usr/include/c++/9/ext/alloc_traits.h:61:53: error: no type named 'size_type' in 'struct std::allocator_traits<std::allocator<char> >'
   61 |     typedef typename _Base_type::size_type          size_type;
      |                                                     ^~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:62:53: error: no type named 'difference_type' in 'struct std::allocator_traits<std::allocator<char> >'
   62 |     typedef typename _Base_type::difference_type    difference_type;
      |                                                     ^~~~~~~~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:70:23: error: no members matching '__gnu_cxx::__alloc_traits<std::allocator<char>, char>::_Base_type {aka std::allocator_traits<std::allocator<char> >}::max_size' in '__gnu_cxx::__alloc_traits<std::allocator<char>, char>::_Base_type' {aka 'struct std::allocator_traits<std::allocator<char> >'}
   70 |     using _Base_type::max_size;
      |                       ^~~~~~~~
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h: In function 'int std::__cxx11::stoi(const string&, size_t*, int)':
/usr/include/c++/9/bits/basic_string.h:6508:19: error: no matching function for call to '__stoa<long int, int>(long int (*)(const char*, char**, int) throw (), const char [5], const char*, size_t*&, int&)'
 6508 |      __idx, __base); }
      |                   ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6508:6: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6508 |      __idx, __base); }
      |      ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'long int std::__cxx11::stol(const string&, size_t*, int)':
/usr/include/c++/9/bits/basic_string.h:6513:22: error: no matching function for call to '__stoa(long int (*)(const char*, char**, int) throw (), const char [5], const char*, size_t*&, int&)'
 6513 |         __idx, __base); }
      |                      ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6513:9: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6513 |         __idx, __base); }
      |         ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'long unsigned int std::__cxx11::stoul(const string&, size_t*, int)':
/usr/include/c++/9/bits/basic_string.h:6518:22: error: no matching function for call to '__stoa(long unsigned int (*)(const char*, char**, int) throw (), const char [6], const char*, size_t*&, int&)'
 6518 |         __idx, __base); }
      |                      ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6518:9: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6518 |         __idx, __base); }
      |         ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'long long int std::__cxx11::stoll(const string&, size_t*, int)':
/usr/include/c++/9/bits/basic_string.h:6523:22: error: no matching function for call to '__stoa(long long int (*)(const char*, char**, int) throw (), const char [6], const char*, size_t*&, int&)'
 6523 |         __idx, __base); }
      |                      ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6523:9: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6523 |         __idx, __base); }
      |         ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'long long unsigned int std::__cxx11::stoull(const string&, size_t*, int)':
/usr/include/c++/9/bits/basic_string.h:6528:22: error: no matching function for call to '__stoa(long long unsigned int (*)(const char*, char**, int) throw (), const char [7], const char*, size_t*&, int&)'
 6528 |         __idx, __base); }
      |                      ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6528:9: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6528 |         __idx, __base); }
      |         ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'float std::__cxx11::stof(const string&, size_t*)':
/usr/include/c++/9/bits/basic_string.h:6533:72: error: no matching function for call to '__stoa(float (*)(const char*, char**) throw (), const char [5], const char*, size_t*&)'
 6533 |   { return __gnu_cxx::__stoa(&std::strtof, "stof", __str.c_str(), __idx); }
      |                                                                        ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6533:67: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6533 |   { return __gnu_cxx::__stoa(&std::strtof, "stof", __str.c_str(), __idx); }
      |                                                                   ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'double std::__cxx11::stod(const string&, size_t*)':
/usr/include/c++/9/bits/basic_string.h:6537:72: error: no matching function for call to '__stoa(double (*)(const char*, char**) throw (), const char [5], const char*, size_t*&)'
 6537 |   { return __gnu_cxx::__stoa(&std::strtod, "stod", __str.c_str(), __idx); }
      |                                                                        ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6537:67: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6537 |   { return __gnu_cxx::__stoa(&std::strtod, "stod", __str.c_str(), __idx); }
      |                                                                   ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'long double std::__cxx11::stold(const string&, size_t*)':
/usr/include/c++/9/bits/basic_string.h:6541:74: error: no matching function for call to '__stoa(long double (*)(const char*, char**) throw (), const char [6], const char*, size_t*&)'
 6541 |   { return __gnu_cxx::__stoa(&std::strtold, "stold", __str.c_str(), __idx); }
      |                                                                          ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6541:69: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6541 |   { return __gnu_cxx::__stoa(&std::strtold, "stold", __str.c_str(), __idx); }
      |                                                                     ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'std::string std::__cxx11::to_string(int)':
/usr/include/c++/9/bits/basic_string.h:6551:20: error: no matching function for call to '__to_xstring<std::string>(int (*)(char*, size_t, const char*, __va_list_tag*) throw (), long unsigned int, const char [3], int&)'
 6551 |         "%d", __val); }
      |                    ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6551:20: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6551 |         "%d", __val); }
      |                    ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::string std::__cxx11::to_string(unsigned int)':
/usr/include/c++/9/bits/basic_string.h:6557:20: error: no matching function for call to '__to_xstring<std::string>(int (*)(char*, size_t, const char*, __va_list_tag*) throw (), long unsigned int, const char [3], unsigned int&)'
 6557 |         "%u", __val); }
      |                    ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6557:20: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6557 |         "%u", __val); }
      |                    ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::string std::__cxx11::to_string(long int)':
/usr/include/c++/9/bits/basic_string.h:6562:21: error: no matching function for call to '__to_xstring<std::string>(int (*)(char*, size_t, const char*, __va_list_tag*) throw (), long unsigned int, const char [4], long int&)'
 6562 |         "%ld", __val); }
      |                     ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6562:21: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6562 |         "%ld", __val); }
      |                     ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::string std::__cxx11::to_string(long unsigned int)':
/usr/include/c++/9/bits/basic_string.h:6568:21: error: no matching function for call to '__to_xstring<std::string>(int (*)(char*, size_t, const char*, __va_list_tag*) throw (), long unsigned int, const char [4], long unsigned int&)'
 6568 |         "%lu", __val); }
      |                     ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6568:21: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6568 |         "%lu", __val); }
      |                     ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::string std::__cxx11::to_string(long long int)':
/usr/include/c++/9/bits/basic_string.h:6574:22: error: no matching function for call to '__to_xstring<std::string>(int (*)(char*, size_t, const char*, __va_list_tag*) throw (), long unsigned int, const char [5], long long int&)'
 6574 |         "%lld", __val); }
      |                      ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6574:22: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6574 |         "%lld", __val); }
      |                      ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::string std::__cxx11::to_string(long long unsigned int)':
/usr/include/c++/9/bits/basic_string.h:6580:22: error: no matching function for call to '__to_xstring<std::string>(int (*)(char*, size_t, const char*, __va_list_tag*) throw (), long unsigned int, const char [5], long long unsigned int&)'
 6580 |         "%llu", __val); }
      |                      ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6580:22: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6580 |         "%llu", __val); }
      |                      ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::string std::__cxx11::to_string(float)':
/usr/include/c++/9/bits/basic_string.h:6588:20: error: no matching function for call to '__to_xstring<std::string>(int (*)(char*, size_t, const char*, __va_list_tag*) throw (), const int&, const char [3], float&)'
 6588 |         "%f", __val);
      |                    ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6588:20: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6588 |         "%f", __val);
      |                    ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::string std::__cxx11::to_string(double)':
/usr/include/c++/9/bits/basic_string.h:6597:20: error: no matching function for call to '__to_xstring<std::string>(int (*)(char*, size_t, const char*, __va_list_tag*) throw (), const int&, const char [3], double&)'
 6597 |         "%f", __val);
      |                    ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6597:20: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6597 |         "%f", __val);
      |                    ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::string std::__cxx11::to_string(long double)':
/usr/include/c++/9/bits/basic_string.h:6606:21: error: no matching function for call to '__to_xstring<std::string>(int (*)(char*, size_t, const char*, __va_list_tag*) throw (), const int&, const char [4], long double&)'
 6606 |         "%Lf", __val);
      |                     ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6606:21: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6606 |         "%Lf", __val);
      |                     ^
In file included from /usr/include/c++/9/bits/basic_string.h:40,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/alloc_traits.h: In instantiation of 'struct __gnu_cxx::__alloc_traits<std::allocator<wchar_t>, wchar_t>':
/usr/include/c++/9/bits/basic_string.h:84:24:   required from 'class std::__cxx11::basic_string<wchar_t>'
/usr/include/c++/9/bits/basic_string.h:6613:68:   required from here
/usr/include/c++/9/ext/alloc_traits.h:61:53: error: no type named 'size_type' in 'struct std::allocator_traits<std::allocator<wchar_t> >'
   61 |     typedef typename _Base_type::size_type          size_type;
      |                                                     ^~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:62:53: error: no type named 'difference_type' in 'struct std::allocator_traits<std::allocator<wchar_t> >'
   62 |     typedef typename _Base_type::difference_type    difference_type;
      |                                                     ^~~~~~~~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:70:23: error: no members matching '__gnu_cxx::__alloc_traits<std::allocator<wchar_t>, wchar_t>::_Base_type {aka std::allocator_traits<std::allocator<wchar_t> >}::max_size' in '__gnu_cxx::__alloc_traits<std::allocator<wchar_t>, wchar_t>::_Base_type' {aka 'struct std::allocator_traits<std::allocator<wchar_t> >'}
   70 |     using _Base_type::max_size;
      |                       ^~~~~~~~
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h: In function 'int std::__cxx11::stoi(const wstring&, size_t*, int)':
/usr/include/c++/9/bits/basic_string.h:6614:19: error: no matching function for call to '__stoa<long int, int>(long int (*)(const wchar_t*, wchar_t**, int) throw (), const char [5], const wchar_t*, size_t*&, int&)'
 6614 |      __idx, __base); }
      |                   ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6614:6: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6614 |      __idx, __base); }
      |      ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'long int std::__cxx11::stol(const wstring&, size_t*, int)':
/usr/include/c++/9/bits/basic_string.h:6619:22: error: no matching function for call to '__stoa(long int (*)(const wchar_t*, wchar_t**, int) throw (), const char [5], const wchar_t*, size_t*&, int&)'
 6619 |         __idx, __base); }
      |                      ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6619:9: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6619 |         __idx, __base); }
      |         ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'long unsigned int std::__cxx11::stoul(const wstring&, size_t*, int)':
/usr/include/c++/9/bits/basic_string.h:6624:22: error: no matching function for call to '__stoa(long unsigned int (*)(const wchar_t*, wchar_t**, int) throw (), const char [6], const wchar_t*, size_t*&, int&)'
 6624 |         __idx, __base); }
      |                      ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6624:9: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6624 |         __idx, __base); }
      |         ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'long long int std::__cxx11::stoll(const wstring&, size_t*, int)':
/usr/include/c++/9/bits/basic_string.h:6629:22: error: no matching function for call to '__stoa(long long int (*)(const wchar_t*, wchar_t**, int) throw (), const char [6], const wchar_t*, size_t*&, int&)'
 6629 |         __idx, __base); }
      |                      ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6629:9: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6629 |         __idx, __base); }
      |         ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'long long unsigned int std::__cxx11::stoull(const wstring&, size_t*, int)':
/usr/include/c++/9/bits/basic_string.h:6634:22: error: no matching function for call to '__stoa(long long unsigned int (*)(const wchar_t*, wchar_t**, int) throw (), const char [7], const wchar_t*, size_t*&, int&)'
 6634 |         __idx, __base); }
      |                      ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6634:9: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6634 |         __idx, __base); }
      |         ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'float std::__cxx11::stof(const wstring&, size_t*)':
/usr/include/c++/9/bits/basic_string.h:6639:72: error: no matching function for call to '__stoa(float (*)(const wchar_t*, wchar_t**) throw (), const char [5], const wchar_t*, size_t*&)'
 6639 |   { return __gnu_cxx::__stoa(&std::wcstof, "stof", __str.c_str(), __idx); }
      |                                                                        ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6639:67: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6639 |   { return __gnu_cxx::__stoa(&std::wcstof, "stof", __str.c_str(), __idx); }
      |                                                                   ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'double std::__cxx11::stod(const wstring&, size_t*)':
/usr/include/c++/9/bits/basic_string.h:6643:72: error: no matching function for call to '__stoa(double (*)(const wchar_t*, wchar_t**) throw (), const char [5], const wchar_t*, size_t*&)'
 6643 |   { return __gnu_cxx::__stoa(&std::wcstod, "stod", __str.c_str(), __idx); }
      |                                                                        ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6643:67: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6643 |   { return __gnu_cxx::__stoa(&std::wcstod, "stod", __str.c_str(), __idx); }
      |                                                                   ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'long double std::__cxx11::stold(const wstring&, size_t*)':
/usr/include/c++/9/bits/basic_string.h:6647:74: error: no matching function for call to '__stoa(long double (*)(const wchar_t*, wchar_t**) throw (), const char [6], const wchar_t*, size_t*&)'
 6647 |   { return __gnu_cxx::__stoa(&std::wcstold, "stold", __str.c_str(), __idx); }
      |                                                                          ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:54:5: note: candidate: 'template<class _TRet, class _Ret, class _CharT, class ... _Base> _Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, int*, _Base ...)'
   54 |     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
      |     ^~~~~~
/usr/include/c++/9/ext/string_conversions.h:54:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6647:69: note:   cannot convert '__idx' (type 'size_t*' {aka 'long unsigned int*'}) to type 'int*'
 6647 |   { return __gnu_cxx::__stoa(&std::wcstold, "stold", __str.c_str(), __idx); }
      |                                                                     ^~~~~
/usr/include/c++/9/bits/basic_string.h: In function 'std::wstring std::__cxx11::to_wstring(int)':
/usr/include/c++/9/bits/basic_string.h:6654:22: error: no matching function for call to '__to_xstring<std::wstring>(int (*)(wchar_t*, size_t, const wchar_t*, __va_list_tag*) throw (), long unsigned int, const wchar_t [3], int&)'
 6654 |          L"%d", __val); }
      |                      ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6654:22: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6654 |          L"%d", __val); }
      |                      ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::wstring std::__cxx11::to_wstring(unsigned int)':
/usr/include/c++/9/bits/basic_string.h:6660:22: error: no matching function for call to '__to_xstring<std::wstring>(int (*)(wchar_t*, size_t, const wchar_t*, __va_list_tag*) throw (), long unsigned int, const wchar_t [3], unsigned int&)'
 6660 |          L"%u", __val); }
      |                      ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6660:22: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6660 |          L"%u", __val); }
      |                      ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::wstring std::__cxx11::to_wstring(long int)':
/usr/include/c++/9/bits/basic_string.h:6665:23: error: no matching function for call to '__to_xstring<std::wstring>(int (*)(wchar_t*, size_t, const wchar_t*, __va_list_tag*) throw (), long unsigned int, const wchar_t [4], long int&)'
 6665 |          L"%ld", __val); }
      |                       ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6665:23: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6665 |          L"%ld", __val); }
      |                       ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::wstring std::__cxx11::to_wstring(long unsigned int)':
/usr/include/c++/9/bits/basic_string.h:6671:23: error: no matching function for call to '__to_xstring<std::wstring>(int (*)(wchar_t*, size_t, const wchar_t*, __va_list_tag*) throw (), long unsigned int, const wchar_t [4], long unsigned int&)'
 6671 |          L"%lu", __val); }
      |                       ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6671:23: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6671 |          L"%lu", __val); }
      |                       ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::wstring std::__cxx11::to_wstring(long long int)':
/usr/include/c++/9/bits/basic_string.h:6677:24: error: no matching function for call to '__to_xstring<std::wstring>(int (*)(wchar_t*, size_t, const wchar_t*, __va_list_tag*) throw (), long unsigned int, const wchar_t [5], long long int&)'
 6677 |          L"%lld", __val); }
      |                        ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6677:24: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6677 |          L"%lld", __val); }
      |                        ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::wstring std::__cxx11::to_wstring(long long unsigned int)':
/usr/include/c++/9/bits/basic_string.h:6683:24: error: no matching function for call to '__to_xstring<std::wstring>(int (*)(wchar_t*, size_t, const wchar_t*, __va_list_tag*) throw (), long unsigned int, const wchar_t [5], long long unsigned int&)'
 6683 |          L"%llu", __val); }
      |                        ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6683:24: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6683 |          L"%llu", __val); }
      |                        ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::wstring std::__cxx11::to_wstring(float)':
/usr/include/c++/9/bits/basic_string.h:6691:22: error: no matching function for call to '__to_xstring<std::wstring>(int (*)(wchar_t*, size_t, const wchar_t*, __va_list_tag*) throw (), const int&, const wchar_t [3], float&)'
 6691 |          L"%f", __val);
      |                      ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6691:22: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6691 |          L"%f", __val);
      |                      ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::wstring std::__cxx11::to_wstring(double)':
/usr/include/c++/9/bits/basic_string.h:6700:22: error: no matching function for call to '__to_xstring<std::wstring>(int (*)(wchar_t*, size_t, const wchar_t*, __va_list_tag*) throw (), const int&, const wchar_t [3], double&)'
 6700 |          L"%f", __val);
      |                      ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6700:22: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6700 |          L"%f", __val);
      |                      ^
/usr/include/c++/9/bits/basic_string.h: In function 'std::wstring std::__cxx11::to_wstring(long double)':
/usr/include/c++/9/bits/basic_string.h:6709:23: error: no matching function for call to '__to_xstring<std::wstring>(int (*)(wchar_t*, size_t, const wchar_t*, __va_list_tag*) throw (), const int&, const wchar_t [4], long double&)'
 6709 |          L"%Lf", __val);
      |                       ^
In file included from /usr/include/c++/9/bits/basic_string.h:6496,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/string_conversions.h:99:5: note: candidate: 'template<class _String, class _CharT> _String __gnu_cxx::__to_xstring(int (*)(_CharT*, int, const _CharT*, __va_list_tag*), int, const _CharT*, ...)'
   99 |     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
      |     ^~~~~~~~~~~~
/usr/include/c++/9/ext/string_conversions.h:99:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h:6709:23: note:   mismatched types 'int' and 'size_t' {aka 'long unsigned int'}
 6709 |          L"%Lf", __val);
      |                       ^
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h: In member function 'size_t std::hash<std::__cxx11::basic_string<char> >::operator()(const string&) const':
/usr/include/c++/9/bits/basic_string.h:6738:54: error: 'const string' {aka 'const class std::__cxx11::basic_string<char>'} has no member named 'length'
 6738 |       { return std::_Hash_impl::hash(__s.data(), __s.length()); }
      |                                                      ^~~~~~
/usr/include/c++/9/bits/basic_string.h: In member function 'size_t std::hash<std::__cxx11::basic_string<wchar_t> >::operator()(const wstring&) const':
/usr/include/c++/9/bits/basic_string.h:6754:42: error: 'const wstring' {aka 'const class std::__cxx11::basic_string<wchar_t>'} has no member named 'length'
 6754 |                                      __s.length() * sizeof(wchar_t)); }
      |                                          ^~~~~~
In file included from /usr/include/c++/9/bits/basic_string.h:40,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/alloc_traits.h: In instantiation of 'struct __gnu_cxx::__alloc_traits<std::allocator<char16_t>, char16_t>':
/usr/include/c++/9/bits/basic_string.h:84:24:   required from 'class std::__cxx11::basic_string<char16_t>'
/usr/include/c++/9/bits/basic_string.h:6787:41:   required from here
/usr/include/c++/9/ext/alloc_traits.h:61:53: error: no type named 'size_type' in 'struct std::allocator_traits<std::allocator<char16_t> >'
   61 |     typedef typename _Base_type::size_type          size_type;
      |                                                     ^~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:62:53: error: no type named 'difference_type' in 'struct std::allocator_traits<std::allocator<char16_t> >'
   62 |     typedef typename _Base_type::difference_type    difference_type;
      |                                                     ^~~~~~~~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:70:23: error: no members matching '__gnu_cxx::__alloc_traits<std::allocator<char16_t>, char16_t>::_Base_type {aka std::allocator_traits<std::allocator<char16_t> >}::max_size' in '__gnu_cxx::__alloc_traits<std::allocator<char16_t>, char16_t>::_Base_type' {aka 'struct std::allocator_traits<std::allocator<char16_t> >'}
   70 |     using _Base_type::max_size;
      |                       ^~~~~~~~
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h: In member function 'size_t std::hash<std::__cxx11::basic_string<char16_t> >::operator()(const u16string&) const':
/usr/include/c++/9/bits/basic_string.h:6788:42: error: 'const u16string' {aka 'const class std::__cxx11::basic_string<char16_t>'} has no member named 'length'
 6788 |                                      __s.length() * sizeof(char16_t)); }
      |                                          ^~~~~~
In file included from /usr/include/c++/9/bits/basic_string.h:40,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/alloc_traits.h: In instantiation of 'struct __gnu_cxx::__alloc_traits<std::allocator<char32_t>, char32_t>':
/usr/include/c++/9/bits/basic_string.h:84:24:   required from 'class std::__cxx11::basic_string<char32_t>'
/usr/include/c++/9/bits/basic_string.h:6802:41:   required from here
/usr/include/c++/9/ext/alloc_traits.h:61:53: error: no type named 'size_type' in 'struct std::allocator_traits<std::allocator<char32_t> >'
   61 |     typedef typename _Base_type::size_type          size_type;
      |                                                     ^~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:62:53: error: no type named 'difference_type' in 'struct std::allocator_traits<std::allocator<char32_t> >'
   62 |     typedef typename _Base_type::difference_type    difference_type;
      |                                                     ^~~~~~~~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:70:23: error: no members matching '__gnu_cxx::__alloc_traits<std::allocator<char32_t>, char32_t>::_Base_type {aka std::allocator_traits<std::allocator<char32_t> >}::max_size' in '__gnu_cxx::__alloc_traits<std::allocator<char32_t>, char32_t>::_Base_type' {aka 'struct std::allocator_traits<std::allocator<char32_t> >'}
   70 |     using _Base_type::max_size;
      |                       ^~~~~~~~
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h: In member function 'size_t std::hash<std::__cxx11::basic_string<char32_t> >::operator()(const u32string&) const':
/usr/include/c++/9/bits/basic_string.h:6803:42: error: 'const u32string' {aka 'const class std::__cxx11::basic_string<char32_t>'} has no member named 'length'
 6803 |                                      __s.length() * sizeof(char32_t)); }
      |                                          ^~~~~~
In file included from /usr/include/c++/9/bits/locale_facets.h:2655,
                 from /usr/include/c++/9/bits/basic_ios.h:37,
                 from /usr/include/c++/9/ios:44,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/locale_facets.tcc: In member function 'void std::__numpunct_cache<_CharT>::_M_cache(const std::locale&)':
/usr/include/c++/9/bits/locale_facets.tcc:88:27: error: 'const string' {aka 'const class std::__cxx11::basic_string<char>'} has no member named 'size'
   88 |    _M_grouping_size = __g.size();
      |                           ^~~~
/usr/include/c++/9/bits/locale_facets.tcc:90:8: error: 'const string' {aka 'const class std::__cxx11::basic_string<char>'} has no member named 'copy'
   90 |    __g.copy(__grouping, _M_grouping_size);
      |        ^~~~
/usr/include/c++/9/bits/locale_facets.tcc: In member function '_InIter std::num_get<_CharT, _InIter>::_M_extract_float(_InIter, _InIter, std::ios_base&, std::ios_base::iostate&, std::string&) const':
/usr/include/c++/9/bits/locale_facets.tcc:211:19: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'reserve'
  211 |  __found_grouping.reserve(32);
      |                   ^~~~~~~
/usr/include/c++/9/bits/locale_facets.tcc:296:28: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'size'
  296 |       if (__found_grouping.size())
      |                            ^~~~
/usr/include/c++/9/bits/locale_facets.tcc:319:28: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'size'
  319 |       if (__found_grouping.size() && !__found_dec)
      |                            ^~~~
/usr/include/c++/9/bits/locale_facets.tcc:355:28: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'size'
  355 |       if (__found_grouping.size())
      |                            ^~~~
/usr/include/c++/9/bits/locale_facets.tcc: In member function '_InIter std::num_get<_CharT, _InIter>::_M_extract_int(_InIter, _InIter, std::ios_base&, std::ios_base::iostate&, _ValueT&) const':
/usr/include/c++/9/bits/locale_facets.tcc:469:21: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'reserve'
  469 |    __found_grouping.reserve(32);
      |                     ^~~~~~~
/usr/include/c++/9/bits/locale_facets.tcc:555:23: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'size'
  555 |  if (__found_grouping.size())
      |                       ^~~~
/usr/include/c++/9/bits/locale_facets.tcc:568:56: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'size'
  568 |  if ((!__sep_pos && !__found_zero && !__found_grouping.size())
      |                                                        ^~~~
/usr/include/c++/9/bits/locale_facets.tcc: In member function 'virtual _InIter std::num_get<_CharT, _InIter>::do_get(std::num_get<_CharT, _InIter>::iter_type, std::num_get<_CharT, _InIter>::iter_type, std::ios_base&, std::ios_base::iostate&, float&) const':
/usr/include/c++/9/bits/locale_facets.tcc:695:14: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'reserve'
  695 |       __xtrc.reserve(32);
      |              ^~~~~~~
/usr/include/c++/9/bits/locale_facets.tcc: In member function 'virtual _InIter std::num_get<_CharT, _InIter>::do_get(std::num_get<_CharT, _InIter>::iter_type, std::num_get<_CharT, _InIter>::iter_type, std::ios_base&, std::ios_base::iostate&, double&) const':
/usr/include/c++/9/bits/locale_facets.tcc:710:14: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'reserve'
  710 |       __xtrc.reserve(32);
      |              ^~~~~~~
/usr/include/c++/9/bits/locale_facets.tcc: In member function 'virtual _InIter std::num_get<_CharT, _InIter>::do_get(std::num_get<_CharT, _InIter>::iter_type, std::num_get<_CharT, _InIter>::iter_type, std::ios_base&, std::ios_base::iostate&, long double&) const':
/usr/include/c++/9/bits/locale_facets.tcc:742:14: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'reserve'
  742 |       __xtrc.reserve(32);
      |              ^~~~~~~
In file included from /usr/include/c++/9/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/utility: At global scope:
/usr/include/c++/9/utility:109:17: error: 'std::size_t' has not been declared
  109 |   template<std::size_t __i, typename _Tp>
      |                 ^~~~~~
/usr/include/c++/9/utility:110:12: error: no default argument for '_Tp'
  110 |     struct tuple_element;
      |            ^~~~~~~~~~~~~
/usr/include/c++/9/utility:113:17: error: 'std::size_t' has not been declared
  113 |   template<std::size_t __i, typename _Tp>
      |                 ^~~~~~
/usr/include/c++/9/utility:114:54: error: '__i' was not declared in this scope
  114 |     using __tuple_element_t = typename tuple_element<__i, _Tp>::type;
      |                                                      ^~~
/usr/include/c++/9/utility:114:62: error: template argument 1 is invalid
  114 |     using __tuple_element_t = typename tuple_element<__i, _Tp>::type;
      |                                                              ^
/usr/include/c++/9/utility:116:17: error: 'std::size_t' has not been declared
  116 |   template<std::size_t __i, typename _Tp>
      |                 ^~~~~~
/usr/include/c++/9/utility:117:26: error: '__i' was not declared in this scope
  117 |     struct tuple_element<__i, const _Tp>
      |                          ^~~
/usr/include/c++/9/utility:117:40: error: template argument 1 is invalid
  117 |     struct tuple_element<__i, const _Tp>
      |                                        ^
/usr/include/c++/9/utility:122:17: error: 'std::size_t' has not been declared
  122 |   template<std::size_t __i, typename _Tp>
      |                 ^~~~~~
/usr/include/c++/9/utility:123:26: error: '__i' was not declared in this scope
  123 |     struct tuple_element<__i, volatile _Tp>
      |                          ^~~
/usr/include/c++/9/utility:123:43: error: template argument 1 is invalid
  123 |     struct tuple_element<__i, volatile _Tp>
      |                                           ^
/usr/include/c++/9/utility:128:17: error: 'std::size_t' has not been declared
  128 |   template<std::size_t __i, typename _Tp>
      |                 ^~~~~~
/usr/include/c++/9/utility:129:26: error: '__i' was not declared in this scope
  129 |     struct tuple_element<__i, const volatile _Tp>
      |                          ^~~
/usr/include/c++/9/utility:129:49: error: template argument 1 is invalid
  129 |     struct tuple_element<__i, const volatile _Tp>
      |                                                 ^
/usr/include/c++/9/utility:154:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  154 |     : public integral_constant<std::size_t, 2> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/utility:154:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  154 |     : public integral_constant<std::size_t, 2> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/utility:154:46: error: template argument 1 is invalid
  154 |     : public integral_constant<std::size_t, 2> { };
      |                                              ^
/usr/include/c++/9/utility:154:46: note: invalid template non-type parameter
/usr/include/c++/9/utility:166:17: error: 'std::size_t' has not been declared
  166 |   template<std::size_t _Int>
      |                 ^~~~~~
/usr/include/c++/9/utility:217:17: error: 'std::size_t' has not been declared
  217 |   template<std::size_t _Int, class _Tp1, class _Tp2>
      |                 ^~~~~~
/usr/include/c++/9/utility:218:38: error: '_Int' was not declared in this scope
  218 |     constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
      |                                      ^~~~
/usr/include/c++/9/utility:218:64: error: template argument 1 is invalid
  218 |     constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
      |                                                                ^~
/usr/include/c++/9/utility: In function 'constexpr int& std::get(std::pair<_Tp1, _Tp2>&)':
/usr/include/c++/9/utility:220:25: error: '_Int' was not declared in this scope
  220 |     { return __pair_get<_Int>::__get(__in); }
      |                         ^~~~
/usr/include/c++/9/utility:220:29: error: template argument 1 is invalid
  220 |     { return __pair_get<_Int>::__get(__in); }
      |                             ^
/usr/include/c++/9/utility: At global scope:
/usr/include/c++/9/utility:222:17: error: 'std::size_t' has not been declared
  222 |   template<std::size_t _Int, class _Tp1, class _Tp2>
      |                 ^~~~~~
/usr/include/c++/9/utility:223:38: error: '_Int' was not declared in this scope
  223 |     constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
      |                                      ^~~~
/usr/include/c++/9/utility:223:64: error: template argument 1 is invalid
  223 |     constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
      |                                                                ^~
/usr/include/c++/9/utility: In function 'constexpr int&& std::get(std::pair<_Tp1, _Tp2>&&)':
/usr/include/c++/9/utility:225:25: error: '_Int' was not declared in this scope
  225 |     { return __pair_get<_Int>::__move_get(std::move(__in)); }
      |                         ^~~~
/usr/include/c++/9/utility:225:29: error: template argument 1 is invalid
  225 |     { return __pair_get<_Int>::__move_get(std::move(__in)); }
      |                             ^
/usr/include/c++/9/utility: At global scope:
/usr/include/c++/9/utility:227:17: error: 'std::size_t' has not been declared
  227 |   template<std::size_t _Int, class _Tp1, class _Tp2>
      |                 ^~~~~~
/usr/include/c++/9/utility:228:44: error: '_Int' was not declared in this scope
  228 |     constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
      |                                            ^~~~
/usr/include/c++/9/utility:228:70: error: template argument 1 is invalid
  228 |     constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
      |                                                                      ^~
/usr/include/c++/9/utility: In function 'constexpr const int& std::get(const std::pair<_Tp1, _Tp2>&)':
/usr/include/c++/9/utility:230:25: error: '_Int' was not declared in this scope
  230 |     { return __pair_get<_Int>::__const_get(__in); }
      |                         ^~~~
/usr/include/c++/9/utility:230:29: error: template argument 1 is invalid
  230 |     { return __pair_get<_Int>::__const_get(__in); }
      |                             ^
/usr/include/c++/9/utility: At global scope:
/usr/include/c++/9/utility:232:17: error: 'std::size_t' has not been declared
  232 |   template<std::size_t _Int, class _Tp1, class _Tp2>
      |                 ^~~~~~
/usr/include/c++/9/utility:233:44: error: '_Int' was not declared in this scope
  233 |     constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
      |                                            ^~~~
/usr/include/c++/9/utility:233:70: error: template argument 1 is invalid
  233 |     constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
      |                                                                      ^~
/usr/include/c++/9/utility: In function 'constexpr const int&& std::get(const std::pair<_Tp1, _Tp2>&&)':
/usr/include/c++/9/utility:235:25: error: '_Int' was not declared in this scope
  235 |     { return __pair_get<_Int>::__const_move_get(std::move(__in)); }
      |                         ^~~~
/usr/include/c++/9/utility:235:29: error: template argument 1 is invalid
  235 |     { return __pair_get<_Int>::__const_move_get(std::move(__in)); }
      |                             ^
/usr/include/c++/9/utility: At global scope:
/usr/include/c++/9/utility:310:58: note: invalid template non-type parameter
  310 |       using __type = _Index_tuple<__integer_pack(_Num)...>;
      |                                                          ^
In file included from /usr/include/c++/9/bits/stl_algo.h:62,
                 from /usr/include/c++/9/algorithm:62,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/bits/stl_tempbuf.h: In function 'std::pair<_Tp*, long int> std::get_temporary_buffer(ptrdiff_t)':
/usr/include/c++/9/bits/stl_tempbuf.h:95:20: error: too many arguments to function 'void* operator new(long unsigned int)'
   95 |        std::nothrow));
      |                    ^
In file included from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/array: At global scope:
/usr/include/c++/9/array:47:31: error: 'std::size_t' has not been declared
   47 |   template<typename _Tp, std::size_t _Nm>
      |                               ^~~~~~
/usr/include/c++/9/array:50:25: error: '_Nm' was not declared in this scope
   50 |       typedef _Tp _Type[_Nm];
      |                         ^~~
/usr/include/c++/9/array:55:20: error: '_Type' does not name a type; did you mean '_Tp'?
   55 |       _S_ref(const _Type& __t, std::size_t __n) noexcept
      |                    ^~~~~
      |                    _Tp
/usr/include/c++/9/array:55:37: error: 'std::size_t' has not been declared
   55 |       _S_ref(const _Type& __t, std::size_t __n) noexcept
      |                                     ^~~~~~
/usr/include/c++/9/array:59:20: error: '_Type' does not name a type; did you mean '_Tp'?
   59 |       _S_ptr(const _Type& __t) noexcept
      |                    ^~~~~
      |                    _Tp
/usr/include/c++/9/array:93:31: error: 'std::size_t' has not been declared
   93 |   template<typename _Tp, std::size_t _Nm>
      |                               ^~~~~~
/usr/include/c++/9/array:103:20: error: 'size_t' in namespace 'std' does not name a type
  103 |       typedef std::size_t                           size_type;
      |                    ^~~~~~
/usr/include/c++/9/array:104:20: error: 'ptrdiff_t' in namespace 'std' does not name a type
  104 |       typedef std::ptrdiff_t                          difference_type;
      |                    ^~~~~~~~~
/usr/include/c++/9/array:109:51: error: '_Nm' was not declared in this scope
  109 |       typedef _GLIBCXX_STD_C::__array_traits<_Tp, _Nm> _AT_Type;
      |                                                   ^~~
/usr/include/c++/9/array:109:54: error: template argument 2 is invalid
  109 |       typedef _GLIBCXX_STD_C::__array_traits<_Tp, _Nm> _AT_Type;
      |                                                      ^
/usr/include/c++/9/array:110:16: error: '_AT_Type' is not a class, namespace, or enumeration
  110 |       typename _AT_Type::_Type                         _M_elems;
      |                ^~~~~~~~
/usr/include/c++/9/array:121:16: error: '_AT_Type' is not a class, namespace, or enumeration
  121 |       noexcept(_AT_Type::_Is_nothrow_swappable::value)
      |                ^~~~~~~~
/usr/include/c++/9/array:174:17: error: 'size_type' does not name a type; did you mean 'true_type'?
  174 |       constexpr size_type
      |                 ^~~~~~~~~
      |                 true_type
/usr/include/c++/9/array:177:17: error: 'size_type' does not name a type; did you mean 'true_type'?
  177 |       constexpr size_type
      |                 ^~~~~~~~~
      |                 true_type
/usr/include/c++/9/array:185:18: error: 'size_type' has not been declared
  185 |       operator[](size_type __n) noexcept
      |                  ^~~~~~~~~
/usr/include/c++/9/array:189:18: error: 'size_type' has not been declared
  189 |       operator[](size_type __n) const noexcept
      |                  ^~~~~~~~~
/usr/include/c++/9/array:193:10: error: 'size_type' has not been declared
  193 |       at(size_type __n)
      |          ^~~~~~~~~
/usr/include/c++/9/array:203:10: error: 'size_type' has not been declared
  203 |       at(size_type __n) const
      |          ^~~~~~~~~
/usr/include/c++/9/array:250:31: error: 'std::size_t' has not been declared
  250 |   template<typename _Tp, std::size_t _Nm>
      |                               ^~~~~~
/usr/include/c++/9/array:252:33: error: '_Nm' was not declared in this scope
  252 |     operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                 ^~~
/usr/include/c++/9/array:252:36: error: template argument 2 is invalid
  252 |     operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                    ^
/usr/include/c++/9/array:252:63: error: '_Nm' was not declared in this scope
  252 |     operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                                               ^~~
/usr/include/c++/9/array:252:66: error: template argument 2 is invalid
  252 |     operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                                                  ^
/usr/include/c++/9/array:252:5: error: 'bool std::operator==(const int&, const int&)' must have an argument of class or enumerated type
  252 |     operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |     ^~~~~~~~
/usr/include/c++/9/array:255:31: error: 'std::size_t' has not been declared
  255 |   template<typename _Tp, std::size_t _Nm>
      |                               ^~~~~~
/usr/include/c++/9/array:257:33: error: '_Nm' was not declared in this scope
  257 |     operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                 ^~~
/usr/include/c++/9/array:257:36: error: template argument 2 is invalid
  257 |     operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                    ^
/usr/include/c++/9/array:257:63: error: '_Nm' was not declared in this scope
  257 |     operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                                               ^~~
/usr/include/c++/9/array:257:66: error: template argument 2 is invalid
  257 |     operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                                                  ^
/usr/include/c++/9/array:257:5: error: 'bool std::operator!=(const int&, const int&)' must have an argument of class or enumerated type
  257 |     operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |     ^~~~~~~~
/usr/include/c++/9/array:260:31: error: 'std::size_t' has not been declared
  260 |   template<typename _Tp, std::size_t _Nm>
      |                               ^~~~~~
/usr/include/c++/9/array:262:32: error: '_Nm' was not declared in this scope
  262 |     operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
      |                                ^~~
/usr/include/c++/9/array:262:35: error: template argument 2 is invalid
  262 |     operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
      |                                   ^
/usr/include/c++/9/array:262:60: error: '_Nm' was not declared in this scope
  262 |     operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
      |                                                            ^~~
/usr/include/c++/9/array:262:63: error: template argument 2 is invalid
  262 |     operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
      |                                                               ^
/usr/include/c++/9/array:262:5: error: 'bool std::operator<(const int&, const int&)' must have an argument of class or enumerated type
  262 |     operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
      |     ^~~~~~~~
/usr/include/c++/9/array:268:31: error: 'std::size_t' has not been declared
  268 |   template<typename _Tp, std::size_t _Nm>
      |                               ^~~~~~
/usr/include/c++/9/array:270:32: error: '_Nm' was not declared in this scope
  270 |     operator>(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                ^~~
/usr/include/c++/9/array:270:35: error: template argument 2 is invalid
  270 |     operator>(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                   ^
/usr/include/c++/9/array:270:62: error: '_Nm' was not declared in this scope
  270 |     operator>(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                                              ^~~
/usr/include/c++/9/array:270:65: error: template argument 2 is invalid
  270 |     operator>(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                                                 ^
/usr/include/c++/9/array:270:5: error: 'bool std::operator>(const int&, const int&)' must have an argument of class or enumerated type
  270 |     operator>(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |     ^~~~~~~~
/usr/include/c++/9/array:273:31: error: 'std::size_t' has not been declared
  273 |   template<typename _Tp, std::size_t _Nm>
      |                               ^~~~~~
/usr/include/c++/9/array:275:33: error: '_Nm' was not declared in this scope
  275 |     operator<=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                 ^~~
/usr/include/c++/9/array:275:36: error: template argument 2 is invalid
  275 |     operator<=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                    ^
/usr/include/c++/9/array:275:63: error: '_Nm' was not declared in this scope
  275 |     operator<=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                                               ^~~
/usr/include/c++/9/array:275:66: error: template argument 2 is invalid
  275 |     operator<=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                                                  ^
/usr/include/c++/9/array:275:5: error: 'bool std::operator<=(const int&, const int&)' must have an argument of class or enumerated type
  275 |     operator<=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |     ^~~~~~~~
/usr/include/c++/9/array:278:31: error: 'std::size_t' has not been declared
  278 |   template<typename _Tp, std::size_t _Nm>
      |                               ^~~~~~
/usr/include/c++/9/array:280:33: error: '_Nm' was not declared in this scope
  280 |     operator>=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                 ^~~
/usr/include/c++/9/array:280:36: error: template argument 2 is invalid
  280 |     operator>=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                    ^
/usr/include/c++/9/array:280:63: error: '_Nm' was not declared in this scope
  280 |     operator>=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                                               ^~~
/usr/include/c++/9/array:280:66: error: template argument 2 is invalid
  280 |     operator>=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |                                                                  ^
/usr/include/c++/9/array:280:5: error: 'bool std::operator>=(const int&, const int&)' must have an argument of class or enumerated type
  280 |     operator>=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
      |     ^~~~~~~~
/usr/include/c++/9/array:284:31: error: 'std::size_t' has not been declared
  284 |   template<typename _Tp, std::size_t _Nm>
      |                               ^~~~~~
/usr/include/c++/9/array:294:21: error: '_Nm' was not declared in this scope
  294 |     swap(array<_Tp, _Nm>& __one, array<_Tp, _Nm>& __two)
      |                     ^~~
/usr/include/c++/9/array:294:24: error: template argument 2 is invalid
  294 |     swap(array<_Tp, _Nm>& __one, array<_Tp, _Nm>& __two)
      |                        ^
/usr/include/c++/9/array:294:45: error: '_Nm' was not declared in this scope
  294 |     swap(array<_Tp, _Nm>& __one, array<_Tp, _Nm>& __two)
      |                                             ^~~
/usr/include/c++/9/array:294:48: error: template argument 2 is invalid
  294 |     swap(array<_Tp, _Nm>& __one, array<_Tp, _Nm>& __two)
      |                                                ^
/usr/include/c++/9/array:295:29: error: request for member 'swap' in '__one', which is of non-class type 'int'
  295 |     noexcept(noexcept(__one.swap(__two)))
      |                             ^~~~
/usr/include/c++/9/array: In function 'void std::swap(int&, int&)':
/usr/include/c++/9/array:296:13: error: request for member 'swap' in '__one', which is of non-class type 'int'
  296 |     { __one.swap(__two); }
      |             ^~~~
/usr/include/c++/9/array: At global scope:
/usr/include/c++/9/array:305:17: error: 'std::size_t' has not been declared
  305 |   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
      |                 ^~~~~~
/usr/include/c++/9/array:305:49: error: 'std::size_t' has not been declared
  305 |   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
      |                                                 ^~~~~~
/usr/include/c++/9/array:307:20: error: '_Nm' was not declared in this scope
  307 |     get(array<_Tp, _Nm>& __arr) noexcept
      |                    ^~~
/usr/include/c++/9/array:307:23: error: template argument 2 is invalid
  307 |     get(array<_Tp, _Nm>& __arr) noexcept
      |                       ^
/usr/include/c++/9/array: In function 'constexpr _Tp& std::get(int&)':
/usr/include/c++/9/array:309:21: error: '_Int' was not declared in this scope
  309 |       static_assert(_Int < _Nm, "array index is within bounds");
      |                     ^~~~
/usr/include/c++/9/array:309:28: error: '_Nm' was not declared in this scope
  309 |       static_assert(_Int < _Nm, "array index is within bounds");
      |                            ^~~
/usr/include/c++/9/array:311:15: error: request for member '_M_elems' in '__arr', which is of non-class type 'int'
  311 |  _S_ref(__arr._M_elems, _Int);
      |               ^~~~~~~~
/usr/include/c++/9/array: At global scope:
/usr/include/c++/9/array:314:17: error: 'std::size_t' has not been declared
  314 |   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
      |                 ^~~~~~
/usr/include/c++/9/array:314:49: error: 'std::size_t' has not been declared
  314 |   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
      |                                                 ^~~~~~
/usr/include/c++/9/array:316:20: error: '_Nm' was not declared in this scope
  316 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |                    ^~~
/usr/include/c++/9/array:316:23: error: template argument 2 is invalid
  316 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |                       ^
/usr/include/c++/9/array: In function 'constexpr _Tp&& std::get(int&&)':
/usr/include/c++/9/array:318:21: error: '_Int' was not declared in this scope
  318 |       static_assert(_Int < _Nm, "array index is within bounds");
      |                     ^~~~
/usr/include/c++/9/array:318:28: error: '_Nm' was not declared in this scope
  318 |       static_assert(_Int < _Nm, "array index is within bounds");
      |                            ^~~
/usr/include/c++/9/array:319:55: error: no matching function for call to 'get<_Int>(int&)'
  319 |       return std::move(_GLIBCXX_STD_C::get<_Int>(__arr));
      |                                                       ^
In file included from /usr/include/c++/9/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/utility:219:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int& std::get(std::pair<_Tp1, _Tp2>&)'
  219 |     get(std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:219:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:224:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int&& std::get(std::pair<_Tp1, _Tp2>&&)'
  224 |     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:224:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:229:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int& std::get(const std::pair<_Tp1, _Tp2>&)'
  229 |     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:229:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:234:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int&& std::get(const std::pair<_Tp1, _Tp2>&&)'
  234 |     get(const std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:234:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/array:307:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp& std::get(int&)'
  307 |     get(array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:307:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:316:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp&& std::get(int&&)'
  316 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:316:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array: At global scope:
/usr/include/c++/9/array:322:17: error: 'std::size_t' has not been declared
  322 |   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
      |                 ^~~~~~
/usr/include/c++/9/array:322:49: error: 'std::size_t' has not been declared
  322 |   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
      |                                                 ^~~~~~
/usr/include/c++/9/array:324:26: error: '_Nm' was not declared in this scope
  324 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |                          ^~~
/usr/include/c++/9/array:324:29: error: template argument 2 is invalid
  324 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |                             ^
/usr/include/c++/9/array: In function 'constexpr const _Tp& std::get(const int&)':
/usr/include/c++/9/array:326:21: error: '_Int' was not declared in this scope
  326 |       static_assert(_Int < _Nm, "array index is within bounds");
      |                     ^~~~
/usr/include/c++/9/array:326:28: error: '_Nm' was not declared in this scope
  326 |       static_assert(_Int < _Nm, "array index is within bounds");
      |                            ^~~
/usr/include/c++/9/array:328:15: error: request for member '_M_elems' in '__arr', which is of non-class type 'const int'
  328 |  _S_ref(__arr._M_elems, _Int);
      |               ^~~~~~~~
/usr/include/c++/9/array: At global scope:
/usr/include/c++/9/array:331:17: error: 'std::size_t' has not been declared
  331 |   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
      |                 ^~~~~~
/usr/include/c++/9/array:331:49: error: 'std::size_t' has not been declared
  331 |   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
      |                                                 ^~~~~~
/usr/include/c++/9/array:333:26: error: '_Nm' was not declared in this scope
  333 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |                          ^~~
/usr/include/c++/9/array:333:29: error: template argument 2 is invalid
  333 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |                             ^
/usr/include/c++/9/array: In function 'constexpr const _Tp&& std::get(const int&&)':
/usr/include/c++/9/array:335:21: error: '_Int' was not declared in this scope
  335 |       static_assert(_Int < _Nm, "array index is within bounds");
      |                     ^~~~
/usr/include/c++/9/array:335:28: error: '_Nm' was not declared in this scope
  335 |       static_assert(_Int < _Nm, "array index is within bounds");
      |                            ^~~
/usr/include/c++/9/array:336:55: error: no matching function for call to 'get<_Int>(const int&)'
  336 |       return std::move(_GLIBCXX_STD_C::get<_Int>(__arr));
      |                                                       ^
In file included from /usr/include/c++/9/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/utility:219:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int& std::get(std::pair<_Tp1, _Tp2>&)'
  219 |     get(std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:219:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:224:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int&& std::get(std::pair<_Tp1, _Tp2>&&)'
  224 |     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:224:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:229:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int& std::get(const std::pair<_Tp1, _Tp2>&)'
  229 |     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:229:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:234:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int&& std::get(const std::pair<_Tp1, _Tp2>&&)'
  234 |     get(const std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:234:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/array:307:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp& std::get(int&)'
  307 |     get(array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:307:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:316:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp&& std::get(int&&)'
  316 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:316:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:324:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp& std::get(const int&)'
  324 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:324:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:333:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp&& std::get(const int&&)'
  333 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:333:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array: At global scope:
/usr/include/c++/9/array:353:31: error: 'std::size_t' has not been declared
  353 |   template<typename _Tp, std::size_t _Nm>
      |                               ^~~~~~
/usr/include/c++/9/array:354:50: error: '_Nm' was not declared in this scope
  354 |     struct tuple_size<_GLIBCXX_STD_C::array<_Tp, _Nm>>
      |                                                  ^~~
/usr/include/c++/9/array:354:50: error: template argument 2 is invalid
/usr/include/c++/9/array:354:53: error: template argument 1 is invalid
  354 |     struct tuple_size<_GLIBCXX_STD_C::array<_Tp, _Nm>>
      |                                                     ^~
/usr/include/c++/9/array:355:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  355 |     : public integral_constant<std::size_t, _Nm> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/array:355:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  355 |     : public integral_constant<std::size_t, _Nm> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/array:355:45: error: '_Nm' was not declared in this scope
  355 |     : public integral_constant<std::size_t, _Nm> { };
      |                                             ^~~
/usr/include/c++/9/array:355:48: error: template argument 1 is invalid
  355 |     : public integral_constant<std::size_t, _Nm> { };
      |                                                ^
/usr/include/c++/9/array:355:48: error: template argument 2 is invalid
/usr/include/c++/9/array:358:17: error: 'std::size_t' has not been declared
  358 |   template<std::size_t _Int, typename _Tp>
      |                 ^~~~~~
/usr/include/c++/9/array:362:17: error: 'std::size_t' has not been declared
  362 |   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
      |                 ^~~~~~
/usr/include/c++/9/array:362:49: error: 'std::size_t' has not been declared
  362 |   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
      |                                                 ^~~~~~
/usr/include/c++/9/array:363:26: error: '_Int' was not declared in this scope
  363 |     struct tuple_element<_Int, _GLIBCXX_STD_C::array<_Tp, _Nm>>
      |                          ^~~~
/usr/include/c++/9/array:363:59: error: '_Nm' was not declared in this scope
  363 |     struct tuple_element<_Int, _GLIBCXX_STD_C::array<_Tp, _Nm>>
      |                                                           ^~~
/usr/include/c++/9/array:363:59: error: template argument 2 is invalid
/usr/include/c++/9/array:363:62: error: template argument 1 is invalid
  363 |     struct tuple_element<_Int, _GLIBCXX_STD_C::array<_Tp, _Nm>>
      |                                                              ^~
/usr/include/c++/9/array:363:62: error: template argument 2 is invalid
/usr/include/c++/9/array:369:31: error: 'std::size_t' has not been declared
  369 |   template<typename _Tp, std::size_t _Nm>
      |                               ^~~~~~
/usr/include/c++/9/array:370:60: error: '_Nm' was not declared in this scope
  370 |     struct __is_tuple_like_impl<_GLIBCXX_STD_C::array<_Tp, _Nm>> : true_type
      |                                                            ^~~
/usr/include/c++/9/array:370:60: error: template argument 2 is invalid
/usr/include/c++/9/array:370:63: error: template argument 1 is invalid
  370 |     struct __is_tuple_like_impl<_GLIBCXX_STD_C::array<_Tp, _Nm>> : true_type
      |                                                               ^~
In file included from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/tuple:68:17: error: 'std::size_t' has not been declared
   68 |   template<std::size_t _Idx, typename _Head,
      |                 ^~~~~~
/usr/include/c++/9/tuple:70:12: error: no default argument for '_Head'
   70 |     struct _Head_base;
      |            ^~~~~~~~~~
/usr/include/c++/9/tuple:72:17: error: 'std::size_t' has not been declared
   72 |   template<std::size_t _Idx, typename _Head>
      |                 ^~~~~~
/usr/include/c++/9/tuple:73:23: error: '_Idx' was not declared in this scope
   73 |     struct _Head_base<_Idx, _Head, true>
      |                       ^~~~
/usr/include/c++/9/tuple:73:40: error: template argument 1 is invalid
   73 |     struct _Head_base<_Idx, _Head, true>
      |                                        ^
/usr/include/c++/9/tuple:119:17: error: 'std::size_t' has not been declared
  119 |   template<std::size_t _Idx, typename _Head>
      |                 ^~~~~~
/usr/include/c++/9/tuple:120:23: error: '_Idx' was not declared in this scope
  120 |     struct _Head_base<_Idx, _Head, false>
      |                       ^~~~
/usr/include/c++/9/tuple:120:41: error: template argument 1 is invalid
  120 |     struct _Head_base<_Idx, _Head, false>
      |                                         ^
/usr/include/c++/9/tuple:176:17: error: 'std::size_t' has not been declared
  176 |   template<std::size_t _Idx, typename... _Elements>
      |                 ^~~~~~
/usr/include/c++/9/tuple:184:17: error: 'std::size_t' has not been declared
  184 |   template<std::size_t _Idx, typename _Head, typename... _Tail>
      |                 ^~~~~~
/usr/include/c++/9/tuple:185:24: error: '_Idx' was not declared in this scope
  185 |     struct _Tuple_impl<_Idx, _Head, _Tail...>
      |                        ^~~~
/usr/include/c++/9/tuple:185:45: error: template argument 1 is invalid
  185 |     struct _Tuple_impl<_Idx, _Head, _Tail...>
      |                                             ^
/usr/include/c++/9/tuple:186:26: error: '_Idx' was not declared in this scope
  186 |     : public _Tuple_impl<_Idx + 1, _Tail...>,
      |                          ^~~~
/usr/include/c++/9/tuple:186:44: error: template argument 1 is invalid
  186 |     : public _Tuple_impl<_Idx + 1, _Tail...>,
      |                                            ^
/usr/include/c++/9/tuple:187:26: error: '_Idx' was not declared in this scope
  187 |       private _Head_base<_Idx, _Head>
      |                          ^~~~
/usr/include/c++/9/tuple:187:37: error: template argument 1 is invalid
  187 |       private _Head_base<_Idx, _Head>
      |                                     ^
/usr/include/c++/9/tuple:325:17: error: 'std::size_t' has not been declared
  325 |   template<std::size_t _Idx, typename _Head>
      |                 ^~~~~~
/usr/include/c++/9/tuple:326:24: error: '_Idx' was not declared in this scope
  326 |     struct _Tuple_impl<_Idx, _Head>
      |                        ^~~~
/usr/include/c++/9/tuple:326:35: error: template argument 1 is invalid
  326 |     struct _Tuple_impl<_Idx, _Head>
      |                                   ^
/usr/include/c++/9/tuple:327:26: error: '_Idx' was not declared in this scope
  327 |     : private _Head_base<_Idx, _Head>
      |                          ^~~~
/usr/include/c++/9/tuple:327:37: error: template argument 1 is invalid
  327 |     : private _Head_base<_Idx, _Head>
      |                                     ^
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_Elements>::tuple()':
/usr/include/c++/9/tuple:562:9: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  562 |       : _Inherited() { }
      |         ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_Elements>::tuple()':
/usr/include/c++/9/tuple:572:9: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  572 |       : _Inherited() { }
      |         ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_Elements>::tuple(const _Elements& ...)':
/usr/include/c++/9/tuple:589:9: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  589 |       : _Inherited(__elements...) { }
      |         ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_Elements>::tuple(const _Elements& ...)':
/usr/include/c++/9/tuple:600:9: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  600 |       : _Inherited(__elements...) { }
      |         ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_Elements>::tuple(_UElements&& ...)':
/usr/include/c++/9/tuple:627:11: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  627 |         : _Inherited(std::forward<_UElements>(__elements)...) { }
      |           ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_Elements>::tuple(_UElements&& ...)':
/usr/include/c++/9/tuple:638:4: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  638 |  : _Inherited(std::forward<_UElements>(__elements)...) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_Elements>::tuple(const std::tuple<_Args1 ...>&)':
/usr/include/c++/9/tuple:659:11: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  659 |         : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
      |           ^~~~~~~~~~
/usr/include/c++/9/tuple:659:69: error: expected '>' before '&' token
  659 |         : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
      |                                                                     ^
/usr/include/c++/9/tuple:659:69: error: expected '(' before '&' token
  659 |         : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
      |                                                                     ^
      |                                                                     (
/usr/include/c++/9/tuple:659:70: error: expected primary-expression before '>' token
  659 |         : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
      |                                                                      ^
/usr/include/c++/9/tuple:660:11: error: expected '{' at end of input
  660 |         { }
      |           ^
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_Elements>::tuple(const std::tuple<_Args1 ...>&)':
/usr/include/c++/9/tuple:671:11: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  671 |         : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
      |           ^~~~~~~~~~
/usr/include/c++/9/tuple:671:69: error: expected '>' before '&' token
  671 |         : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
      |                                                                     ^
/usr/include/c++/9/tuple:671:69: error: expected '(' before '&' token
  671 |         : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
      |                                                                     ^
      |                                                                     (
/usr/include/c++/9/tuple:671:70: error: expected primary-expression before '>' token
  671 |         : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
      |                                                                      ^
/usr/include/c++/9/tuple:672:11: error: expected '{' at end of input
  672 |         { }
      |           ^
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_Elements>::tuple(std::tuple<_Args1 ...>&&)':
/usr/include/c++/9/tuple:683:11: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  683 |         : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
      |           ^~~~~~~~~~
/usr/include/c++/9/tuple:683:63: error: expected '>' before '&&' token
  683 |         : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
      |                                                               ^~
/usr/include/c++/9/tuple:683:63: error: expected '(' before '&&' token
  683 |         : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
      |                                                               ^~
      |                                                               (
/usr/include/c++/9/tuple:683:65: error: expected identifier before '>' token
  683 |         : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
      |                                                                 ^
/usr/include/c++/9/tuple:683:76: error: expected '{' at end of input
  683 |         : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
      |                                                                            ^
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_Elements>::tuple(std::tuple<_Args1 ...>&&)':
/usr/include/c++/9/tuple:694:11: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  694 |         : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
      |           ^~~~~~~~~~
/usr/include/c++/9/tuple:694:63: error: expected '>' before '&&' token
  694 |         : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
      |                                                               ^~
/usr/include/c++/9/tuple:694:63: error: expected '(' before '&&' token
  694 |         : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
      |                                                               ^~
      |                                                               (
/usr/include/c++/9/tuple:694:65: error: expected identifier before '>' token
  694 |         : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
      |                                                                 ^
/usr/include/c++/9/tuple:694:76: error: expected '{' at end of input
  694 |         : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
      |                                                                            ^
/usr/include/c++/9/tuple: In constructor 'std::tuple<_Elements>::tuple(std::allocator_arg_t, const _Alloc&)':
/usr/include/c++/9/tuple:700:4: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  700 |  : _Inherited(__tag, __a) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_Elements>::tuple(std::allocator_arg_t, const _Alloc&, const _Elements& ...)':
/usr/include/c++/9/tuple:711:4: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  711 |  : _Inherited(__tag, __a, __elements...) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_Elements>::tuple(std::allocator_arg_t, const _Alloc&, const _Elements& ...)':
/usr/include/c++/9/tuple:722:4: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  722 |  : _Inherited(__tag, __a, __elements...) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_Elements>::tuple(std::allocator_arg_t, const _Alloc&, _UElements&& ...)':
/usr/include/c++/9/tuple:732:4: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  732 |  : _Inherited(__tag, __a, std::forward<_UElements>(__elements)...)
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_Elements>::tuple(std::allocator_arg_t, const _Alloc&, _UElements&& ...)':
/usr/include/c++/9/tuple:743:4: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  743 |  : _Inherited(__tag, __a, std::forward<_UElements>(__elements)...)
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_Elements>::tuple(std::allocator_arg_t, const _Alloc&, const std::tuple<_Elements>&)':
/usr/include/c++/9/tuple:748:4: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  748 |  : _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_Elements>::tuple(std::allocator_arg_t, const _Alloc&, std::tuple<_Elements>&&)':
/usr/include/c++/9/tuple:752:4: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  752 |  : _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_Elements>::tuple(std::allocator_arg_t, const _Alloc&, const std::tuple<_UElements ...>&)':
/usr/include/c++/9/tuple:765:4: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  765 |  : _Inherited(__tag, __a,
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple:766:62: error: expected '>' before '&' token
  766 |               static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
      |                                                              ^
/usr/include/c++/9/tuple:766:62: error: expected '(' before '&' token
  766 |               static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
      |                                                              ^
      |                                                              (
/usr/include/c++/9/tuple:766:63: error: expected primary-expression before '>' token
  766 |               static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
      |                                                               ^
/usr/include/c++/9/tuple:767:4: error: expected '{' at end of input
  767 |  { }
      |    ^
/usr/include/c++/9/tuple: In constructor 'std::tuple<_Elements>::tuple(std::allocator_arg_t, const _Alloc&, const std::tuple<_UElements ...>&)':
/usr/include/c++/9/tuple:780:4: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  780 |  : _Inherited(__tag, __a,
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple:781:62: error: expected '>' before '&' token
  781 |               static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
      |                                                              ^
/usr/include/c++/9/tuple:781:62: error: expected '(' before '&' token
  781 |               static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
      |                                                              ^
      |                                                              (
/usr/include/c++/9/tuple:781:63: error: expected primary-expression before '>' token
  781 |               static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
      |                                                               ^
/usr/include/c++/9/tuple:782:4: error: expected '{' at end of input
  782 |  { }
      |    ^
/usr/include/c++/9/tuple: In constructor 'std::tuple<_Elements>::tuple(std::allocator_arg_t, const _Alloc&, std::tuple<_UElements ...>&&)':
/usr/include/c++/9/tuple:795:4: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  795 |  : _Inherited(__tag, __a,
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple:796:56: error: expected '>' before '&&' token
  796 |               static_cast<_Tuple_impl<0, _UElements...>&&>(__in))
      |                                                        ^~
/usr/include/c++/9/tuple:796:56: error: expected '(' before '&&' token
  796 |               static_cast<_Tuple_impl<0, _UElements...>&&>(__in))
      |                                                        ^~
      |                                                        (
/usr/include/c++/9/tuple:796:58: error: expected identifier before '>' token
  796 |               static_cast<_Tuple_impl<0, _UElements...>&&>(__in))
      |                                                          ^
/usr/include/c++/9/tuple:797:4: error: expected '{' at end of input
  797 |  { }
      |    ^
/usr/include/c++/9/tuple: In constructor 'std::tuple<_Elements>::tuple(std::allocator_arg_t, const _Alloc&, std::tuple<_UElements ...>&&)':
/usr/include/c++/9/tuple:810:4: error: 'typedef int std::tuple<_Elements>::_Inherited' is not a non-static data member of 'std::tuple<_Elements>'
  810 |  : _Inherited(__tag, __a,
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple:811:56: error: expected '>' before '&&' token
  811 |               static_cast<_Tuple_impl<0, _UElements...>&&>(__in))
      |                                                        ^~
/usr/include/c++/9/tuple:811:56: error: expected '(' before '&&' token
  811 |               static_cast<_Tuple_impl<0, _UElements...>&&>(__in))
      |                                                        ^~
      |                                                        (
/usr/include/c++/9/tuple:811:58: error: expected identifier before '>' token
  811 |               static_cast<_Tuple_impl<0, _UElements...>&&>(__in))
      |                                                          ^
/usr/include/c++/9/tuple:812:4: error: expected '{' at end of input
  812 |  { }
      |    ^
/usr/include/c++/9/tuple: In member function 'void std::tuple<_Elements>::swap(std::tuple<_Elements>&)':
/usr/include/c++/9/tuple:858:28: error: qualified-id in declaration before '(' token
  858 |       { _Inherited::_M_swap(__in); }
      |                            ^
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_T1, _T2>::tuple()':
/usr/include/c++/9/tuple:919:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
  919 |  : _Inherited() { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_T1, _T2>::tuple()':
/usr/include/c++/9/tuple:932:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
  932 |  : _Inherited() { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_T1, _T2>::tuple(const _T1&, const _T2&)':
/usr/include/c++/9/tuple:946:11: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
  946 |         : _Inherited(__a1, __a2) { }
      |           ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_T1, _T2>::tuple(const _T1&, const _T2&)':
/usr/include/c++/9/tuple:955:11: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
  955 |         : _Inherited(__a1, __a2) { }
      |           ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_T1, _T2>::tuple(_U1&&, _U2&&)':
/usr/include/c++/9/tuple:969:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
  969 |  : _Inherited(std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_T1, _T2>::tuple(_U1&&, _U2&&)':
/usr/include/c++/9/tuple:979:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
  979 |  : _Inherited(std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_T1, _T2>::tuple(const std::tuple<_U1, _U2>&)':
/usr/include/c++/9/tuple:992:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
  992 |  : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple:992:57: error: expected '>' before '&' token
  992 |  : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
      |                                                         ^
/usr/include/c++/9/tuple:992:57: error: expected '(' before '&' token
  992 |  : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
      |                                                         ^
      |                                                         (
/usr/include/c++/9/tuple:992:58: error: expected primary-expression before '>' token
  992 |  : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
      |                                                          ^
/usr/include/c++/9/tuple:992:69: error: expected '{' at end of input
  992 |  : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
      |                                                                     ^
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_T1, _T2>::tuple(const std::tuple<_U1, _U2>&)':
/usr/include/c++/9/tuple:1001:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1001 |  : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple:1001:57: error: expected '>' before '&' token
 1001 |  : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
      |                                                         ^
/usr/include/c++/9/tuple:1001:57: error: expected '(' before '&' token
 1001 |  : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
      |                                                         ^
      |                                                         (
/usr/include/c++/9/tuple:1001:58: error: expected primary-expression before '>' token
 1001 |  : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
      |                                                          ^
/usr/include/c++/9/tuple:1001:69: error: expected '{' at end of input
 1001 |  : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
      |                                                                     ^
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_T1, _T2>::tuple(std::tuple<_U1, _U2>&&)':
/usr/include/c++/9/tuple:1010:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1010 |  : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple:1010:51: error: expected '>' before '&&' token
 1010 |  : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
      |                                                   ^~
/usr/include/c++/9/tuple:1010:51: error: expected '(' before '&&' token
 1010 |  : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
      |                                                   ^~
      |                                                   (
/usr/include/c++/9/tuple:1010:53: error: expected identifier before '>' token
 1010 |  : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
      |                                                     ^
/usr/include/c++/9/tuple:1010:64: error: expected '{' at end of input
 1010 |  : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
      |                                                                ^
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_T1, _T2>::tuple(std::tuple<_U1, _U2>&&)':
/usr/include/c++/9/tuple:1019:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1019 |  : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple:1019:51: error: expected '>' before '&&' token
 1019 |  : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
      |                                                   ^~
/usr/include/c++/9/tuple:1019:51: error: expected '(' before '&&' token
 1019 |  : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
      |                                                   ^~
      |                                                   (
/usr/include/c++/9/tuple:1019:53: error: expected identifier before '>' token
 1019 |  : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
      |                                                     ^
/usr/include/c++/9/tuple:1019:64: error: expected '{' at end of input
 1019 |  : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
      |                                                                ^
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_T1, _T2>::tuple(const std::pair<_U1, _U2>&)':
/usr/include/c++/9/tuple:1028:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1028 |  : _Inherited(__in.first, __in.second) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_T1, _T2>::tuple(const std::pair<_U1, _U2>&)':
/usr/include/c++/9/tuple:1037:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1037 |  : _Inherited(__in.first, __in.second) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_T1, _T2>::tuple(std::pair<_U1, _U2>&&)':
/usr/include/c++/9/tuple:1046:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1046 |  : _Inherited(std::forward<_U1>(__in.first),
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'constexpr std::tuple<_T1, _T2>::tuple(std::pair<_U1, _U2>&&)':
/usr/include/c++/9/tuple:1056:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1056 |  : _Inherited(std::forward<_U1>(__in.first),
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&)':
/usr/include/c++/9/tuple:1063:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1063 |  : _Inherited(__tag, __a) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&, const _T1&, const _T2&)':
/usr/include/c++/9/tuple:1075:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1075 |  : _Inherited(__tag, __a, __a1, __a2) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&, const _T1&, const _T2&)':
/usr/include/c++/9/tuple:1087:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1087 |  : _Inherited(__tag, __a, __a1, __a2) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&, _U1&&, _U2&&)':
/usr/include/c++/9/tuple:1096:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1096 |  : _Inherited(__tag, __a, std::forward<_U1>(__a1),
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&, _U1&&, _U2&&)':
/usr/include/c++/9/tuple:1107:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1107 |  : _Inherited(__tag, __a, std::forward<_U1>(__a1),
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&, const std::tuple<_T1, _T2>&)':
/usr/include/c++/9/tuple:1112:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1112 |  : _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&, std::tuple<_T1, _T2>&&)':
/usr/include/c++/9/tuple:1116:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1116 |  : _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&, const std::tuple<_U1, _U2>&)':
/usr/include/c++/9/tuple:1126:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1126 |  : _Inherited(__tag, __a,
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple:1127:57: error: expected '>' before '&' token
 1127 |               static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in))
      |                                                         ^
/usr/include/c++/9/tuple:1127:57: error: expected '(' before '&' token
 1127 |               static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in))
      |                                                         ^
      |                                                         (
/usr/include/c++/9/tuple:1127:58: error: expected primary-expression before '>' token
 1127 |               static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in))
      |                                                          ^
/usr/include/c++/9/tuple:1128:4: error: expected '{' at end of input
 1128 |  { }
      |    ^
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&, const std::tuple<_U1, _U2>&)':
/usr/include/c++/9/tuple:1138:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1138 |  : _Inherited(__tag, __a,
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple:1139:57: error: expected '>' before '&' token
 1139 |               static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in))
      |                                                         ^
/usr/include/c++/9/tuple:1139:57: error: expected '(' before '&' token
 1139 |               static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in))
      |                                                         ^
      |                                                         (
/usr/include/c++/9/tuple:1139:58: error: expected primary-expression before '>' token
 1139 |               static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in))
      |                                                          ^
/usr/include/c++/9/tuple:1140:4: error: expected '{' at end of input
 1140 |  { }
      |    ^
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&, std::tuple<_U1, _U2>&&)':
/usr/include/c++/9/tuple:1149:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1149 |  : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in))
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple:1149:63: error: expected '>' before '&&' token
 1149 |  : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in))
      |                                                               ^~
/usr/include/c++/9/tuple:1149:63: error: expected '(' before '&&' token
 1149 |  : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in))
      |                                                               ^~
      |                                                               (
/usr/include/c++/9/tuple:1149:65: error: expected identifier before '>' token
 1149 |  : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in))
      |                                                                 ^
/usr/include/c++/9/tuple:1150:4: error: expected '{' at end of input
 1150 |  { }
      |    ^
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&, std::tuple<_U1, _U2>&&)':
/usr/include/c++/9/tuple:1160:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1160 |  : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in))
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple:1160:63: error: expected '>' before '&&' token
 1160 |  : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in))
      |                                                               ^~
/usr/include/c++/9/tuple:1160:63: error: expected '(' before '&&' token
 1160 |  : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in))
      |                                                               ^~
      |                                                               (
/usr/include/c++/9/tuple:1160:65: error: expected identifier before '>' token
 1160 |  : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in))
      |                                                                 ^
/usr/include/c++/9/tuple:1161:4: error: expected '{' at end of input
 1161 |  { }
      |    ^
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&, const std::pair<_U1, _U2>&)':
/usr/include/c++/9/tuple:1171:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1171 |  : _Inherited(__tag, __a, __in.first, __in.second) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&, const std::pair<_U1, _U2>&)':
/usr/include/c++/9/tuple:1181:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1181 |  : _Inherited(__tag, __a, __in.first, __in.second) { }
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&, std::pair<_U1, _U2>&&)':
/usr/include/c++/9/tuple:1190:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1190 |  : _Inherited(__tag, __a, std::forward<_U1>(__in.first),
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In constructor 'std::tuple<_T1, _T2>::tuple(std::allocator_arg_t, const _Alloc&, std::pair<_U1, _U2>&&)':
/usr/include/c++/9/tuple:1201:4: error: 'typedef int std::tuple<_T1, _T2>::_Inherited' is not a non-static data member of 'std::tuple<_T1, _T2>'
 1201 |  : _Inherited(__tag, __a, std::forward<_U1>(__in.first),
      |    ^~~~~~~~~~
/usr/include/c++/9/tuple: In member function 'void std::tuple<_T1, _T2>::swap(std::tuple<_T1, _T2>&)':
/usr/include/c++/9/tuple:1266:28: error: qualified-id in declaration before '(' token
 1266 |       { _Inherited::_M_swap(__in); }
      |                            ^
/usr/include/c++/9/tuple: At global scope:
/usr/include/c++/9/tuple:1273:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1273 |     : public integral_constant<std::size_t, sizeof...(_Elements)> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/tuple:1273:37: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1273 |     : public integral_constant<std::size_t, sizeof...(_Elements)> { };
      |                                     ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/tuple:1273:65: error: template argument 1 is invalid
 1273 |     : public integral_constant<std::size_t, sizeof...(_Elements)> { };
      |                                                                 ^
/usr/include/c++/9/tuple:1273:65: note: invalid template non-type parameter
/usr/include/c++/9/tuple:1284:17: error: 'std::size_t' has not been declared
 1284 |   template<std::size_t __i, typename _Head, typename... _Tail>
      |                 ^~~~~~
/usr/include/c++/9/tuple:1285:26: error: '__i' was not declared in this scope
 1285 |     struct tuple_element<__i, tuple<_Head, _Tail...> >
      |                          ^~~
/usr/include/c++/9/tuple:1285:54: error: template argument 1 is invalid
 1285 |     struct tuple_element<__i, tuple<_Head, _Tail...> >
      |                                                      ^
/usr/include/c++/9/tuple:1286:21: error: '__i' was not declared in this scope
 1286 |     : tuple_element<__i - 1, tuple<_Tail...> > { };
      |                     ^~~
/usr/include/c++/9/tuple:1286:46: error: template argument 1 is invalid
 1286 |     : tuple_element<__i - 1, tuple<_Tail...> > { };
      |                                              ^
/usr/include/c++/9/tuple:1307:17: error: 'std::size_t' has not been declared
 1307 |   template<std::size_t __i, typename _Head, typename... _Tail>
      |                 ^~~~~~
/usr/include/c++/9/tuple:1309:30: error: '__i' was not declared in this scope
 1309 |     __get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
      |                              ^~~
/usr/include/c++/9/tuple:1309:50: error: template argument 1 is invalid
 1309 |     __get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
      |                                                  ^
/usr/include/c++/9/tuple: In function 'constexpr _Head& std::__get_helper(int&)':
/usr/include/c++/9/tuple:1310:26: error: '__i' was not declared in this scope; did you mean '__t'?
 1310 |     { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
      |                          ^~~
      |                          __t
/usr/include/c++/9/tuple:1310:46: error: template argument 1 is invalid
 1310 |     { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
      |                                              ^
/usr/include/c++/9/tuple: At global scope:
/usr/include/c++/9/tuple:1312:17: error: 'std::size_t' has not been declared
 1312 |   template<std::size_t __i, typename _Head, typename... _Tail>
      |                 ^~~~~~
/usr/include/c++/9/tuple:1314:36: error: '__i' was not declared in this scope
 1314 |     __get_helper(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
      |                                    ^~~
/usr/include/c++/9/tuple:1314:56: error: template argument 1 is invalid
 1314 |     __get_helper(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
      |                                                        ^
/usr/include/c++/9/tuple: In function 'constexpr const _Head& std::__get_helper(const int&)':
/usr/include/c++/9/tuple:1315:26: error: '__i' was not declared in this scope; did you mean '__t'?
 1315 |     { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
      |                          ^~~
      |                          __t
/usr/include/c++/9/tuple:1315:46: error: template argument 1 is invalid
 1315 |     { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
      |                                              ^
/usr/include/c++/9/tuple: At global scope:
/usr/include/c++/9/tuple:1318:17: error: 'std::size_t' has not been declared
 1318 |   template<std::size_t __i, typename... _Elements>
      |                 ^~~~~~
/usr/include/c++/9/tuple:1319:15: error: '__tuple_element_t' does not name a type; did you mean 'tuple_element'?
 1319 |     constexpr __tuple_element_t<__i, tuple<_Elements...>>&
      |               ^~~~~~~~~~~~~~~~~
      |               tuple_element
/usr/include/c++/9/tuple:1324:17: error: 'std::size_t' has not been declared
 1324 |   template<std::size_t __i, typename... _Elements>
      |                 ^~~~~~
/usr/include/c++/9/tuple:1325:21: error: '__tuple_element_t' does not name a type; did you mean 'tuple_element'?
 1325 |     constexpr const __tuple_element_t<__i, tuple<_Elements...>>&
      |                     ^~~~~~~~~~~~~~~~~
      |                     tuple_element
/usr/include/c++/9/tuple:1330:17: error: 'std::size_t' has not been declared
 1330 |   template<std::size_t __i, typename... _Elements>
      |                 ^~~~~~
/usr/include/c++/9/tuple:1331:15: error: '__tuple_element_t' does not name a type; did you mean 'tuple_element'?
 1331 |     constexpr __tuple_element_t<__i, tuple<_Elements...>>&&
      |               ^~~~~~~~~~~~~~~~~
      |               tuple_element
/usr/include/c++/9/tuple:1339:17: error: 'std::size_t' has not been declared
 1339 |   template<std::size_t __i, typename... _Elements>
      |                 ^~~~~~
/usr/include/c++/9/tuple:1340:21: error: '__tuple_element_t' does not name a type; did you mean 'tuple_element'?
 1340 |     constexpr const __tuple_element_t<__i, tuple<_Elements...>>&&
      |                     ^~~~~~~~~~~~~~~~~
      |                     tuple_element
/usr/include/c++/9/tuple:1491:18: error: '__tuple_element_t' was not declared in this scope; did you mean 'tuple_element'?
 1491 |    tuple<_Tp..., __tuple_element_t<_Idx, _Tuple>>,
      |                  ^~~~~~~~~~~~~~~~~
      |                  tuple_element
/usr/include/c++/9/tuple:1491:42: error: template argument 2 is invalid
 1491 |    tuple<_Tp..., __tuple_element_t<_Idx, _Tuple>>,
      |                                          ^~~~~~
/usr/include/c++/9/tuple:1491:48: error: wrong number of template arguments (2, should be 4)
 1491 |    tuple<_Tp..., __tuple_element_t<_Idx, _Tuple>>,
      |                                                ^~
/usr/include/c++/9/tuple:1486:12: note: provided for 'template<long unsigned int <anonymous>, class, class, long unsigned int <anonymous> > struct std::__make_tuple_impl'
 1486 |     struct __make_tuple_impl;
      |            ^~~~~~~~~~~~~~~~~
/usr/include/c++/9/tuple:1492:15: error: expected class-name before '>' token
 1492 |    _Tuple, _Nm>
      |               ^
/usr/include/c++/9/tuple:1492:15: error: expected '{' before '>' token
/usr/include/c++/9/tuple:1495:17: error: 'std::size_t' has not been declared
 1495 |   template<std::size_t _Nm, typename _Tuple, typename... _Tp>
      |                 ^~~~~~
/usr/include/c++/9/tuple:1496:30: error: '_Nm' was not declared in this scope
 1496 |     struct __make_tuple_impl<_Nm, tuple<_Tp...>, _Tuple, _Nm>
      |                              ^~~
/usr/include/c++/9/tuple:1496:58: error: '_Nm' was not declared in this scope
 1496 |     struct __make_tuple_impl<_Nm, tuple<_Tp...>, _Tuple, _Nm>
      |                                                          ^~~
/usr/include/c++/9/tuple:1496:61: error: template argument 1 is invalid
 1496 |     struct __make_tuple_impl<_Nm, tuple<_Tp...>, _Tuple, _Nm>
      |                                                             ^
/usr/include/c++/9/tuple:1496:61: error: template argument 4 is invalid
/usr/include/c++/9/tuple:1567:32: error: 'std::size_t' has not been declared
 1567 |   template<typename _Ret, std::size_t... _Is, typename _Tp, typename... _Tpls>
      |                                ^~~~~~
/usr/include/c++/9/tuple:1568:53: error: '_Is' was not declared in this scope
 1568 |     struct __tuple_concater<_Ret, std::_Index_tuple<_Is...>, _Tp, _Tpls...>
      |                                                     ^~~
/usr/include/c++/9/tuple:1568:56: error: expected parameter pack before '...'
 1568 |     struct __tuple_concater<_Ret, std::_Index_tuple<_Is...>, _Tp, _Tpls...>
      |                                                        ^~~
/usr/include/c++/9/tuple:1568:59: error: template argument 1 is invalid
 1568 |     struct __tuple_concater<_Ret, std::_Index_tuple<_Is...>, _Tp, _Tpls...>
      |                                                           ^
/usr/include/c++/9/tuple:1568:75: error: template argument 2 is invalid
 1568 |     struct __tuple_concater<_Ret, std::_Index_tuple<_Is...>, _Tp, _Tpls...>
      |                                                                           ^
/usr/include/c++/9/tuple:1667:39: error: 'std::size_t' has not been declared
 1667 |     template<typename... _Args1, std::size_t... _Indexes1,
      |                                       ^~~~~~
/usr/include/c++/9/tuple:1668:39: error: 'std::size_t' has not been declared
 1668 |              typename... _Args2, std::size_t... _Indexes2>
      |                                       ^~~~~~
/usr/include/c++/9/tuple:1672:18: error: '_Indexes1' was not declared in this scope
 1672 |     _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>)
      |                  ^~~~~~~~~
/usr/include/c++/9/tuple:1672:27: error: expected parameter pack before '...'
 1672 |     _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>)
      |                           ^~~
/usr/include/c++/9/tuple:1672:30: error: template argument 1 is invalid
 1672 |     _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>)
      |                              ^
/usr/include/c++/9/tuple:1672:46: error: '_Indexes2' was not declared in this scope
 1672 |     _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>)
      |                                              ^~~~~~~~~
/usr/include/c++/9/tuple:1672:55: error: expected parameter pack before '...'
 1672 |     _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>)
      |                                                       ^~~
/usr/include/c++/9/tuple:1672:58: error: template argument 1 is invalid
 1672 |     _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>)
      |                                                          ^
/usr/include/c++/9/tuple:1672:59: error: default argument for template parameter for class enclosing 'std::pair<_T1, _T2>::pair(std::tuple<_Args1 ...>&, std::tuple<_Args2 ...>&, int, int)'
 1672 |     _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>)
      |                                                           ^
/usr/include/c++/9/tuple: In constructor 'std::pair<_T1, _T2>::pair(std::tuple<_Args1 ...>&, std::tuple<_Args2 ...>&, int, int)':
/usr/include/c++/9/tuple:1673:45: error: '_Indexes1' was not declared in this scope
 1673 |       : first(std::forward<_Args1>(std::get<_Indexes1>(__tuple1))...),
      |                                             ^~~~~~~~~
/usr/include/c++/9/tuple:1674:46: error: '_Indexes2' was not declared in this scope
 1674 |         second(std::forward<_Args2>(std::get<_Indexes2>(__tuple2))...)
      |                                              ^~~~~~~~~
In file included from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/functional: At global scope:
/usr/include/c++/9/functional:259:17: error: 'std::size_t' has not been declared
  259 |   template<std::size_t __i, typename _Tuple>
      |                 ^~~~~~
/usr/include/c++/9/functional:261:29: error: '__i' was not declared in this scope
  261 |       = typename enable_if<(__i < tuple_size<_Tuple>::value),
      |                             ^~~
/usr/include/c++/9/functional:262:21: error: '__i' was not declared in this scope
  262 |       tuple_element<__i, _Tuple>>::type::type;
      |                     ^~~
/usr/include/c++/9/functional:262:26: error: template argument 1 is invalid
  262 |       tuple_element<__i, _Tuple>>::type::type;
      |                          ^~~~~~
/usr/include/c++/9/functional:262:32: error: template argument 2 is invalid
  262 |       tuple_element<__i, _Tuple>>::type::type;
      |                                ^~
/usr/include/c++/9/functional:262:36: error: '<expression error>::type' has not been declared
  262 |       tuple_element<__i, _Tuple>>::type::type;
      |                                    ^~~~
/usr/include/c++/9/functional:324:57: error: 'std::size_t' has not been declared
  324 |       template<typename _CVArg, typename... _Args, std::size_t... _Indexes>
      |                                                         ^~~~~~
/usr/include/c++/9/functional:327:28: error: '_Indexes' was not declared in this scope
  327 |         const _Index_tuple<_Indexes...>&) const volatile
      |                            ^~~~~~~~
/usr/include/c++/9/functional:327:36: error: expected parameter pack before '...'
  327 |         const _Index_tuple<_Indexes...>&) const volatile
      |                                    ^~~
/usr/include/c++/9/functional:327:39: error: template argument 1 is invalid
  327 |         const _Index_tuple<_Indexes...>&) const volatile
      |                                       ^
/usr/include/c++/9/functional: In member function 'decltype (__arg((declval<_Args>)()...)) std::_Mu<_Arg, true, false>::__call(_CVArg&, std::tuple<_Args2 ...>&, const int&) const volatile':
/usr/include/c++/9/functional:330:26: error: '_Indexes' was not declared in this scope
  330 |    return __arg(std::get<_Indexes>(std::move(__tuple))...);
      |                          ^~~~~~~~
/usr/include/c++/9/functional:330:55: error: expansion pattern 'get<<expression error> >(std::move(__tuple))' contains no parameter packs
  330 |    return __arg(std::get<_Indexes>(std::move(__tuple))...);
      |                                                       ^~~
/usr/include/c++/9/functional: At global scope:
/usr/include/c++/9/functional:344:2: error: '_Safe_tuple_element_t' does not name a type
  344 |  _Safe_tuple_element_t<(is_placeholder<_Arg>::value - 1), _Tuple>&&
      |  ^~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/functional:368:17: error: 'std::size_t' has not been declared
  368 |   template<std::size_t _Ind, typename... _Tp>
      |                 ^~~~~~
/usr/include/c++/9/functional:371:8: error: '__tuple_element_t' does not name a type; did you mean 'tuple_element'?
  371 |     -> __tuple_element_t<_Ind, tuple<_Tp...>> volatile&
      |        ^~~~~~~~~~~~~~~~~
      |        tuple_element
/usr/include/c++/9/functional:371:25: error: expected initializer before '<' token
  371 |     -> __tuple_element_t<_Ind, tuple<_Tp...>> volatile&
      |                         ^
/usr/include/c++/9/functional:375:17: error: 'std::size_t' has not been declared
  375 |   template<std::size_t _Ind, typename... _Tp>
      |                 ^~~~~~
/usr/include/c++/9/functional:378:8: error: '__tuple_element_t' does not name a type; did you mean 'tuple_element'?
  378 |     -> __tuple_element_t<_Ind, tuple<_Tp...>> const volatile&
      |        ^~~~~~~~~~~~~~~~~
      |        tuple_element
/usr/include/c++/9/functional:378:25: error: expected initializer before '<' token
  378 |     -> __tuple_element_t<_Ind, tuple<_Tp...>> const volatile&
      |                         ^
/usr/include/c++/9/functional:396:58: error: 'std::size_t' has not been declared
  396 |       template<typename _Result, typename... _Args, std::size_t... _Indexes>
      |                                                          ^~~~~~
/usr/include/c++/9/functional:398:48: error: '_Indexes' was not declared in this scope
  398 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
      |                                                ^~~~~~~~
/usr/include/c++/9/functional:398:56: error: expected parameter pack before '...'
  398 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
      |                                                        ^~~
/usr/include/c++/9/functional:398:59: error: template argument 1 is invalid
  398 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
      |                                                           ^
/usr/include/c++/9/functional:406:58: error: 'std::size_t' has not been declared
  406 |       template<typename _Result, typename... _Args, std::size_t... _Indexes>
      |                                                          ^~~~~~
/usr/include/c++/9/functional:408:50: error: '_Indexes' was not declared in this scope
  408 |  __call_c(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
      |                                                  ^~~~~~~~
/usr/include/c++/9/functional:408:58: error: expected parameter pack before '...'
  408 |  __call_c(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
      |                                                          ^~~
/usr/include/c++/9/functional:408:61: error: template argument 1 is invalid
  408 |  __call_c(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
      |                                                             ^
/usr/include/c++/9/functional:416:58: error: 'std::size_t' has not been declared
  416 |       template<typename _Result, typename... _Args, std::size_t... _Indexes>
      |                                                          ^~~~~~
/usr/include/c++/9/functional:419:17: error: '_Indexes' was not declared in this scope
  419 |    _Index_tuple<_Indexes...>) volatile
      |                 ^~~~~~~~
/usr/include/c++/9/functional:419:25: error: expected parameter pack before '...'
  419 |    _Index_tuple<_Indexes...>) volatile
      |                         ^~~
/usr/include/c++/9/functional:419:28: error: template argument 1 is invalid
  419 |    _Index_tuple<_Indexes...>) volatile
      |                            ^
/usr/include/c++/9/functional:427:58: error: 'std::size_t' has not been declared
  427 |       template<typename _Result, typename... _Args, std::size_t... _Indexes>
      |                                                          ^~~~~~
/usr/include/c++/9/functional:430:19: error: '_Indexes' was not declared in this scope
  430 |      _Index_tuple<_Indexes...>) const volatile
      |                   ^~~~~~~~
/usr/include/c++/9/functional:430:27: error: expected parameter pack before '...'
  430 |      _Index_tuple<_Indexes...>) const volatile
      |                           ^~~
/usr/include/c++/9/functional:430:30: error: template argument 1 is invalid
  430 |      _Index_tuple<_Indexes...>) const volatile
      |                              ^
/usr/include/c++/9/functional: In member function '_Result std::_Bind<_Functor(_Bound_args ...)>::__call(std::tuple<_Args2 ...>&&, int)':
/usr/include/c++/9/functional:401:36: error: '_Indexes' was not declared in this scope
  401 |        _Mu<_Bound_args>()(std::get<_Indexes>(_M_bound_args), __args)...
      |                                    ^~~~~~~~
/usr/include/c++/9/functional: In member function '_Result std::_Bind<_Functor(_Bound_args ...)>::__call_c(std::tuple<_Args2 ...>&&, int) const':
/usr/include/c++/9/functional:411:36: error: '_Indexes' was not declared in this scope
  411 |        _Mu<_Bound_args>()(std::get<_Indexes>(_M_bound_args), __args)...
      |                                    ^~~~~~~~
/usr/include/c++/9/functional: In member function '_Result std::_Bind<_Functor(_Bound_args ...)>::__call_v(std::tuple<_Args2 ...>&&, int) volatile':
/usr/include/c++/9/functional:422:27: error: '__volget' was not declared in this scope
  422 |        _Mu<_Bound_args>()(__volget<_Indexes>(_M_bound_args), __args)...
      |                           ^~~~~~~~
/usr/include/c++/9/functional:422:36: error: '_Indexes' was not declared in this scope
  422 |        _Mu<_Bound_args>()(__volget<_Indexes>(_M_bound_args), __args)...
      |                                    ^~~~~~~~
/usr/include/c++/9/functional: In member function '_Result std::_Bind<_Functor(_Bound_args ...)>::__call_c_v(std::tuple<_Args2 ...>&&, int) const volatile':
/usr/include/c++/9/functional:433:27: error: '__volget' was not declared in this scope
  433 |        _Mu<_Bound_args>()(__volget<_Indexes>(_M_bound_args), __args)...
      |                           ^~~~~~~~
/usr/include/c++/9/functional:433:36: error: '_Indexes' was not declared in this scope
  433 |        _Mu<_Bound_args>()(__volget<_Indexes>(_M_bound_args), __args)...
      |                                    ^~~~~~~~
/usr/include/c++/9/functional: At global scope:
/usr/include/c++/9/functional:552:55: error: 'std::size_t' has not been declared
  552 |       template<typename _Res, typename... _Args, std::size_t... _Indexes>
      |                                                       ^~~~~~
/usr/include/c++/9/functional:554:48: error: '_Indexes' was not declared in this scope
  554 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
      |                                                ^~~~~~~~
/usr/include/c++/9/functional:554:56: error: expected parameter pack before '...'
  554 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
      |                                                        ^~~
/usr/include/c++/9/functional:554:59: error: template argument 1 is invalid
  554 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
      |                                                           ^
/usr/include/c++/9/functional:561:55: error: 'std::size_t' has not been declared
  561 |       template<typename _Res, typename... _Args, std::size_t... _Indexes>
      |                                                       ^~~~~~
/usr/include/c++/9/functional:563:48: error: '_Indexes' was not declared in this scope
  563 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
      |                                                ^~~~~~~~
/usr/include/c++/9/functional:563:56: error: expected parameter pack before '...'
  563 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
      |                                                        ^~~
/usr/include/c++/9/functional:563:59: error: template argument 1 is invalid
  563 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
      |                                                           ^
/usr/include/c++/9/functional:570:55: error: 'std::size_t' has not been declared
  570 |       template<typename _Res, typename... _Args, std::size_t... _Indexes>
      |                                                       ^~~~~~
/usr/include/c++/9/functional:572:48: error: '_Indexes' was not declared in this scope
  572 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
      |                                                ^~~~~~~~
/usr/include/c++/9/functional:572:56: error: expected parameter pack before '...'
  572 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
      |                                                        ^~~
/usr/include/c++/9/functional:572:59: error: template argument 1 is invalid
  572 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
      |                                                           ^
/usr/include/c++/9/functional:579:55: error: 'std::size_t' has not been declared
  579 |       template<typename _Res, typename... _Args, std::size_t... _Indexes>
      |                                                       ^~~~~~
/usr/include/c++/9/functional:581:48: error: '_Indexes' was not declared in this scope
  581 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
      |                                                ^~~~~~~~
/usr/include/c++/9/functional:581:56: error: expected parameter pack before '...'
  581 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
      |                                                        ^~~
/usr/include/c++/9/functional:581:59: error: template argument 1 is invalid
  581 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
      |                                                           ^
/usr/include/c++/9/functional:588:55: error: 'std::size_t' has not been declared
  588 |       template<typename _Res, typename... _Args, std::size_t... _Indexes>
      |                                                       ^~~~~~
/usr/include/c++/9/functional:590:48: error: '_Indexes' was not declared in this scope
  590 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) volatile
      |                                                ^~~~~~~~
/usr/include/c++/9/functional:590:56: error: expected parameter pack before '...'
  590 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) volatile
      |                                                        ^~~
/usr/include/c++/9/functional:590:59: error: template argument 1 is invalid
  590 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) volatile
      |                                                           ^
/usr/include/c++/9/functional:597:55: error: 'std::size_t' has not been declared
  597 |       template<typename _Res, typename... _Args, std::size_t... _Indexes>
      |                                                       ^~~~~~
/usr/include/c++/9/functional:599:48: error: '_Indexes' was not declared in this scope
  599 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) volatile
      |                                                ^~~~~~~~
/usr/include/c++/9/functional:599:56: error: expected parameter pack before '...'
  599 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) volatile
      |                                                        ^~~
/usr/include/c++/9/functional:599:59: error: template argument 1 is invalid
  599 |  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) volatile
      |                                                           ^
/usr/include/c++/9/functional:606:55: error: 'std::size_t' has not been declared
  606 |       template<typename _Res, typename... _Args, std::size_t... _Indexes>
      |                                                       ^~~~~~
/usr/include/c++/9/functional:609:22: error: '_Indexes' was not declared in this scope
  609 |         _Index_tuple<_Indexes...>) const volatile
      |                      ^~~~~~~~
/usr/include/c++/9/functional:609:30: error: expected parameter pack before '...'
  609 |         _Index_tuple<_Indexes...>) const volatile
      |                              ^~~
/usr/include/c++/9/functional:609:33: error: template argument 1 is invalid
  609 |         _Index_tuple<_Indexes...>) const volatile
      |                                 ^
/usr/include/c++/9/functional:616:55: error: 'std::size_t' has not been declared
  616 |       template<typename _Res, typename... _Args, std::size_t... _Indexes>
      |                                                       ^~~~~~
/usr/include/c++/9/functional:619:22: error: '_Indexes' was not declared in this scope
  619 |         _Index_tuple<_Indexes...>) const volatile
      |                      ^~~~~~~~
/usr/include/c++/9/functional:619:30: error: expected parameter pack before '...'
  619 |         _Index_tuple<_Indexes...>) const volatile
      |                              ^~~
/usr/include/c++/9/functional:619:33: error: template argument 1 is invalid
  619 |         _Index_tuple<_Indexes...>) const volatile
      |                                 ^
/usr/include/c++/9/functional: In member function 'std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__disable_if_void<_Res> std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__call(std::tuple<_Args2 ...>&&, int)':
/usr/include/c++/9/functional:557:19: error: '_Indexes' was not declared in this scope
  557 |         (std::get<_Indexes>(_M_bound_args), __args)...);
      |                   ^~~~~~~~
/usr/include/c++/9/functional: In member function 'std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__enable_if_void<_Res> std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__call(std::tuple<_Args2 ...>&&, int)':
/usr/include/c++/9/functional:566:19: error: '_Indexes' was not declared in this scope
  566 |         (std::get<_Indexes>(_M_bound_args), __args)...);
      |                   ^~~~~~~~
/usr/include/c++/9/functional: In member function 'std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__disable_if_void<_Res> std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__call(std::tuple<_Args2 ...>&&, int) const':
/usr/include/c++/9/functional:575:19: error: '_Indexes' was not declared in this scope
  575 |         (std::get<_Indexes>(_M_bound_args), __args)...);
      |                   ^~~~~~~~
/usr/include/c++/9/functional: In member function 'std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__enable_if_void<_Res> std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__call(std::tuple<_Args2 ...>&&, int) const':
/usr/include/c++/9/functional:584:19: error: '_Indexes' was not declared in this scope
  584 |         (std::get<_Indexes>(_M_bound_args),  __args)...);
      |                   ^~~~~~~~
/usr/include/c++/9/functional: In member function 'std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__disable_if_void<_Res> std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__call(std::tuple<_Args2 ...>&&, int) volatile':
/usr/include/c++/9/functional:593:10: error: '__volget' was not declared in this scope
  593 |         (__volget<_Indexes>(_M_bound_args), __args)...);
      |          ^~~~~~~~
/usr/include/c++/9/functional:593:19: error: '_Indexes' was not declared in this scope
  593 |         (__volget<_Indexes>(_M_bound_args), __args)...);
      |                   ^~~~~~~~
/usr/include/c++/9/functional: In member function 'std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__enable_if_void<_Res> std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__call(std::tuple<_Args2 ...>&&, int) volatile':
/usr/include/c++/9/functional:602:10: error: '__volget' was not declared in this scope
  602 |         (__volget<_Indexes>(_M_bound_args), __args)...);
      |          ^~~~~~~~
/usr/include/c++/9/functional:602:19: error: '_Indexes' was not declared in this scope
  602 |         (__volget<_Indexes>(_M_bound_args), __args)...);
      |                   ^~~~~~~~
/usr/include/c++/9/functional: In member function 'std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__disable_if_void<_Res> std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__call(std::tuple<_Args2 ...>&&, int) const volatile':
/usr/include/c++/9/functional:612:10: error: '__volget' was not declared in this scope
  612 |         (__volget<_Indexes>(_M_bound_args), __args)...);
      |          ^~~~~~~~
/usr/include/c++/9/functional:612:19: error: '_Indexes' was not declared in this scope
  612 |         (__volget<_Indexes>(_M_bound_args), __args)...);
      |                   ^~~~~~~~
/usr/include/c++/9/functional: In member function 'std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__enable_if_void<_Res> std::_Bind_result<_Result, _Functor(_Bound_args ...)>::__call(std::tuple<_Args2 ...>&&, int) const volatile':
/usr/include/c++/9/functional:622:10: error: '__volget' was not declared in this scope
  622 |         (__volget<_Indexes>(_M_bound_args), __args)...);
      |          ^~~~~~~~
/usr/include/c++/9/functional:622:19: error: '_Indexes' was not declared in this scope
  622 |         (__volget<_Indexes>(_M_bound_args), __args)...);
      |                   ^~~~~~~~
In file included from /usr/include/c++/9/bits/locale_facets_nonio.h:2015,
                 from /usr/include/c++/9/locale:41,
                 from /usr/include/c++/9/iomanip:43,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:72,
                 from foo.cc:2:
/usr/include/c++/9/bits/locale_facets_nonio.tcc: In member function 'void std::__moneypunct_cache<_CharT, _Intl>::_M_cache(const std::locale&)':
/usr/include/c++/9/bits/locale_facets_nonio.tcc:85:27: error: 'const string' {aka 'const class std::__cxx11::basic_string<char>'} has no member named 'size'
   85 |    _M_grouping_size = __g.size();
      |                           ^~~~
/usr/include/c++/9/bits/locale_facets_nonio.tcc:87:8: error: 'const string' {aka 'const class std::__cxx11::basic_string<char>'} has no member named 'copy'
   87 |    __g.copy(__grouping, _M_grouping_size);
      |        ^~~~
/usr/include/c++/9/bits/locale_facets_nonio.tcc: In member function '_InIter std::__cxx11::money_get<_CharT, _InIter>::_M_extract(std::__cxx11::money_get<_CharT, _InIter>::iter_type, std::__cxx11::money_get<_CharT, _InIter>::iter_type, std::ios_base&, std::ios_base::iostate&, std::string&) const':
/usr/include/c++/9/bits/locale_facets_nonio.tcc:162:19: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'reserve'
  162 |    __grouping_tmp.reserve(32);
      |                   ^~~~~~~
/usr/include/c++/9/bits/locale_facets_nonio.tcc:174:8: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'reserve'
  174 |  __res.reserve(32);
      |        ^~~~~~~
/usr/include/c++/9/bits/locale_facets_nonio.tcc:311:16: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'size'
  311 |      if (__res.size() > 1)
      |                ^~~~
/usr/include/c++/9/bits/locale_facets_nonio.tcc:313:35: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'find_first_not_of'
  313 |   const size_type __first = __res.find_first_not_of('0');
      |                                   ^~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/locale_facets_nonio.tcc:314:48: error: 'npos' is not a member of 'std::string' {aka 'std::__cxx11::basic_string<char>'}
  314 |   const bool __only_zeros = __first == string::npos;
      |                                                ^~~~
/usr/include/c++/9/bits/locale_facets_nonio.tcc:316:41: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'size'
  316 |     __res.erase(0, __only_zeros ? __res.size() - 1 : __first);
      |                                         ^~~~
/usr/include/c++/9/bits/locale_facets_nonio.tcc:320:29: error: no match for 'operator[]' (operand types are 'std::string' {aka 'std::__cxx11::basic_string<char>'} and 'int')
  320 |      if (__negative && __res[0] != '0')
      |                             ^
/usr/include/c++/9/bits/locale_facets_nonio.tcc:324:25: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'size'
  324 |      if (__grouping_tmp.size())
      |                         ^~~~
/usr/include/c++/9/bits/locale_facets_nonio.tcc: In member function 'virtual _InIter std::__cxx11::money_get<_CharT, _InIter>::do_get(std::__cxx11::money_get<_CharT, _InIter>::iter_type, std::__cxx11::money_get<_CharT, _InIter>::iter_type, bool, std::ios_base&, std::ios_base::iostate&, std::__cxx11::money_get<_CharT, _InIter>::string_type&) const':
/usr/include/c++/9/bits/locale_facets_nonio.tcc:387:32: error: invalid combination of multiple type-specifiers
  387 |       typedef typename string::size_type                  size_type;
      |                                ^~~~~~~~~
/usr/include/c++/9/bits/locale_facets_nonio.tcc:395:37: error: 'std::string' {aka 'class std::__cxx11::basic_string<char>'} has no member named 'size'
  395 |       const size_type __len = __str.size();
      |                                     ^~~~
In file included from /usr/include/c++/9/bits/stl_list.h:63,
                 from /usr/include/c++/9/list:63,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:79,
                 from foo.cc:2:
/usr/include/c++/9/bits/allocated_ptr.h: At global scope:
/usr/include/c++/9/bits/allocated_ptr.h:78:31: error: declaration of 'operator=' as non-function
   78 |       operator=(std::nullptr_t) noexcept
      |                               ^
/usr/include/c++/9/bits/allocated_ptr.h:78:15: error: expected ';' at end of member declaration
   78 |       operator=(std::nullptr_t) noexcept
      |               ^
      |                ;
/usr/include/c++/9/bits/allocated_ptr.h:78:31: error: invalid use of '::'
   78 |       operator=(std::nullptr_t) noexcept
      |                               ^
/usr/include/c++/9/bits/allocated_ptr.h:78:31: error: expected ';' at end of member declaration
   78 |       operator=(std::nullptr_t) noexcept
      |                               ^
      |                                ;
/usr/include/c++/9/bits/allocated_ptr.h:78:33: error: expected unqualified-id before 'noexcept'
   78 |       operator=(std::nullptr_t) noexcept
      |                                 ^~~~~~~~
In file included from /usr/include/c++/9/bits/stl_list.h:64,
                 from /usr/include/c++/9/list:63,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:79,
                 from foo.cc:2:
/usr/include/c++/9/ext/aligned_buffer.h:61:42: error: invalid use of '::'
   61 |       __aligned_membuf(std::nullptr_t) { }
      |                                          ^
/usr/include/c++/9/ext/aligned_buffer.h:61:42: error: expected ';' at end of member declaration
   61 |       __aligned_membuf(std::nullptr_t) { }
      |                                          ^
      |                                           ;
/usr/include/c++/9/ext/aligned_buffer.h:99:42: error: invalid use of '::'
   99 |       __aligned_buffer(std::nullptr_t) { }
      |                                          ^
/usr/include/c++/9/ext/aligned_buffer.h:99:42: error: expected ';' at end of member declaration
   99 |       __aligned_buffer(std::nullptr_t) { }
      |                                          ^
      |                                           ;
In file included from /usr/include/c++/9/list:63,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:79,
                 from foo.cc:2:
/usr/include/c++/9/bits/stl_list.h:106:12: error: 'size_t' in namespace 'std' does not name a type
  106 |       std::size_t _M_size;
      |            ^~~~~~
/usr/include/c++/9/bits/stl_list.h: In constructor 'std::__detail::_List_node_header::_List_node_header(std::__detail::_List_node_header&&)':
/usr/include/c++/9/bits/stl_list.h:116:9: error: class 'std::__detail::_List_node_header' does not have any field named '_M_size'
  116 |       , _M_size(__x._M_size)
      |         ^~~~~~~
/usr/include/c++/9/bits/stl_list.h:116:21: error: 'struct std::__detail::_List_node_header' has no member named '_M_size'
  116 |       , _M_size(__x._M_size)
      |                     ^~~~~~~
/usr/include/c++/9/bits/stl_list.h: In member function 'void std::__detail::_List_node_header::_M_move_nodes(std::__detail::_List_node_header&&)':
/usr/include/c++/9/bits/stl_list.h:141:6: error: '_M_size' was not declared in this scope
  141 |      _M_size = __x._M_size;
      |      ^~~~~~~
/usr/include/c++/9/bits/stl_list.h:141:20: error: 'struct std::__detail::_List_node_header' has no member named '_M_size'
  141 |      _M_size = __x._M_size;
      |                    ^~~~~~~
/usr/include/c++/9/bits/stl_list.h: In member function 'void std::__detail::_List_node_header::_M_init()':
/usr/include/c++/9/bits/stl_list.h:153:8: error: 'struct std::__detail::_List_node_header' has no member named '_M_size'
  153 |  this->_M_size = 0;
      |        ^~~~~~~
/usr/include/c++/9/bits/stl_list.h: In function 'ptrdiff_t std::__distance(std::_List_const_iterator<_Tp>, std::_List_const_iterator<_Tp>, std::input_iterator_tag)':
/usr/include/c++/9/bits/stl_list.h:2086:56: error: 'const _Sentinel' {aka 'const struct std::__detail::_List_node_header'} has no member named '_M_size'
 2086 |  return static_cast<const _Sentinel*>(__last._M_node)->_M_size;
      |                                                        ^~~~~~~
In file included from /usr/include/c++/9/forward_list:38,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:104,
                 from foo.cc:2:
/usr/include/c++/9/bits/forward_list.h: At global scope:
/usr/include/c++/9/bits/forward_list.h:447:20: error: 'size_t' in namespace 'std' does not name a type
  447 |       typedef std::size_t    size_type;
      |                    ^~~~~~
/usr/include/c++/9/bits/forward_list.h:448:20: error: 'ptrdiff_t' in namespace 'std' does not name a type
  448 |       typedef std::ptrdiff_t    difference_type;
      |                    ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.h:515:29: error: expected ')' before '__n'
  515 |       forward_list(size_type __n, const _Alloc& __al = _Alloc())
      |                   ~         ^~~~
      |                             )
/usr/include/c++/9/bits/forward_list.h:528:29: error: expected ')' before '__n'
  528 |       forward_list(size_type __n, const _Tp& __value,
      |                   ~         ^~~~
      |                             )
/usr/include/c++/9/bits/forward_list.h:672:14: error: 'size_type' has not been declared
  672 |       assign(size_type __n, const _Tp& __val)
      |              ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.h:784:7: error: 'size_type' does not name a type; did you mean 'true_type'?
  784 |       size_type
      |       ^~~~~~~~~
      |       true_type
/usr/include/c++/9/bits/forward_list.h:935:42: error: 'size_type' has not been declared
  935 |       insert_after(const_iterator __pos, size_type __n, const _Tp& __val);
      |                                          ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.h:1057:14: error: 'size_type' has not been declared
 1057 |       resize(size_type __sz);
      |              ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.h:1072:14: error: 'size_type' has not been declared
 1072 |       resize(size_type __sz, const value_type& __val);
      |              ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.h:1304:26: error: 'size_type' has not been declared
 1304 |       _M_fill_initialize(size_type __n, const value_type& __value);
      |                          ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.h:1313:29: error: 'size_type' has not been declared
 1313 |       _M_default_initialize(size_type __n);
      |                             ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.h:1317:53: error: 'size_type' has not been declared
 1317 |       _M_default_insert_after(const_iterator __pos, size_type __n);
      |                                                     ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.h:1377:19: error: 'size_type' has not been declared
 1377 |       _M_assign_n(size_type __n, const _Tp& __val, true_type)
      |                   ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.h:1397:19: error: 'size_type' has not been declared
 1397 |       _M_assign_n(size_type __n, const _Tp& __val, false_type)
      |                   ^~~~~~~~~
In file included from /usr/include/c++/9/forward_list:40,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:104,
                 from foo.cc:2:
/usr/include/c++/9/bits/forward_list.tcc:114:24: error: variable or field '_M_fill_initialize' declared void
  114 |     _M_fill_initialize(size_type __n, const value_type& __value)
      |                        ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.tcc:114:24: error: 'size_type' was not declared in this scope; did you mean 'true_type'?
  114 |     _M_fill_initialize(size_type __n, const value_type& __value)
      |                        ^~~~~~~~~
      |                        true_type
/usr/include/c++/9/bits/forward_list.tcc:114:39: error: expected primary-expression before 'const'
  114 |     _M_fill_initialize(size_type __n, const value_type& __value)
      |                                       ^~~~~
/usr/include/c++/9/bits/forward_list.tcc:127:27: error: variable or field '_M_default_initialize' declared void
  127 |     _M_default_initialize(size_type __n)
      |                           ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.tcc:127:27: error: 'size_type' was not declared in this scope; did you mean 'true_type'?
  127 |     _M_default_initialize(size_type __n)
      |                           ^~~~~~~~~
      |                           true_type
/usr/include/c++/9/bits/forward_list.tcc:164:51: error: 'size_type' has not been declared
  164 |     _M_default_insert_after(const_iterator __pos, size_type __n)
      |                                                   ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.tcc:182:12: error: variable or field 'resize' declared void
  182 |     resize(size_type __sz)
      |            ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.tcc:182:12: error: 'size_type' was not declared in this scope; did you mean 'true_type'?
  182 |     resize(size_type __sz)
      |            ^~~~~~~~~
      |            true_type
/usr/include/c++/9/bits/forward_list.tcc:201:12: error: variable or field 'resize' declared void
  201 |     resize(size_type __sz, const value_type& __val)
      |            ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.tcc:201:12: error: 'size_type' was not declared in this scope; did you mean 'true_type'?
  201 |     resize(size_type __sz, const value_type& __val)
      |            ^~~~~~~~~
      |            true_type
/usr/include/c++/9/bits/forward_list.tcc:201:28: error: expected primary-expression before 'const'
  201 |     resize(size_type __sz, const value_type& __val)
      |                            ^~~~~
/usr/include/c++/9/bits/forward_list.tcc:256:40: error: 'size_type' has not been declared
  256 |     insert_after(const_iterator __pos, size_type __n, const _Tp& __val)
      |                                        ^~~~~~~~~
/usr/include/c++/9/bits/forward_list.tcc: In member function 'std::forward_list<_Tp, _Alloc>::__remove_return_type std::forward_list<_Tp, _Alloc>::remove(const _Tp&)':
/usr/include/c++/9/bits/forward_list.tcc:292:7: error: 'size_type' was not declared in this scope; did you mean 'true_type'?
  292 |       size_type __removed __attribute__((__unused__)) = 0;
      |       ^~~~~~~~~
      |       true_type
/usr/include/c++/9/bits/forward_list.tcc: In member function 'std::forward_list<_Tp, _Alloc>::__remove_return_type std::forward_list<_Tp, _Alloc>::remove_if(_Pred)':
/usr/include/c++/9/bits/forward_list.tcc:326:2: error: 'size_type' was not declared in this scope; did you mean 'true_type'?
  326 |  size_type __removed __attribute__((__unused__)) = 0;
      |  ^~~~~~~~~
      |  true_type
/usr/include/c++/9/bits/forward_list.tcc: In member function 'std::forward_list<_Tp, _Alloc>::__remove_return_type std::forward_list<_Tp, _Alloc>::unique(_BinPred)':
/usr/include/c++/9/bits/forward_list.tcc:351:2: error: 'size_type' was not declared in this scope; did you mean 'true_type'?
  351 |  size_type __removed __attribute__((__unused__)) = 0;
      |  ^~~~~~~~~
      |  true_type
In file included from /usr/include/c++/9/future:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:105,
                 from foo.cc:2:
/usr/include/c++/9/thread: At global scope:
/usr/include/c++/9/thread:243:34: note: invalid template non-type parameter
  243 |    _M_invoke(_Index_tuple<_Ind...>)
      |                                  ^
In file included from /usr/include/c++/9/bits/basic_string.h:40,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/alloc_traits.h: In instantiation of 'struct __gnu_cxx::__alloc_traits<std::allocator<double>, double>':
/usr/include/c++/9/bits/stl_vector.h:84:21:   required from 'struct std::_Vector_base<double, std::allocator<double> >'
/usr/include/c++/9/bits/stl_vector.h:386:11:   required from 'class std::vector<double>'
/usr/include/c++/9/bits/random.h:5324:22:   required from here
/usr/include/c++/9/ext/alloc_traits.h:61:53: error: no type named 'size_type' in 'struct std::allocator_traits<std::allocator<double> >'
   61 |     typedef typename _Base_type::size_type          size_type;
      |                                                     ^~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:62:53: error: no type named 'difference_type' in 'struct std::allocator_traits<std::allocator<double> >'
   62 |     typedef typename _Base_type::difference_type    difference_type;
      |                                                     ^~~~~~~~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:70:23: error: no members matching '__gnu_cxx::__alloc_traits<std::allocator<double>, double>::_Base_type {aka std::allocator_traits<std::allocator<double> >}::max_size' in '__gnu_cxx::__alloc_traits<std::allocator<double>, double>::_Base_type' {aka 'struct std::allocator_traits<std::allocator<double> >'}
   70 |     using _Base_type::max_size;
      |                       ^~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h: In instantiation of 'struct __gnu_cxx::__alloc_traits<std::allocator<unsigned int>, unsigned int>':
/usr/include/c++/9/bits/stl_vector.h:84:21:   required from 'struct std::_Vector_base<unsigned int, std::allocator<unsigned int> >'
/usr/include/c++/9/bits/stl_vector.h:386:11:   required from 'class std::vector<unsigned int>'
/usr/include/c++/9/bits/random.h:6093:30:   required from here
/usr/include/c++/9/ext/alloc_traits.h:61:53: error: no type named 'size_type' in 'struct std::allocator_traits<std::allocator<unsigned int> >'
   61 |     typedef typename _Base_type::size_type          size_type;
      |                                                     ^~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:62:53: error: no type named 'difference_type' in 'struct std::allocator_traits<std::allocator<unsigned int> >'
   62 |     typedef typename _Base_type::difference_type    difference_type;
      |                                                     ^~~~~~~~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:70:23: error: no members matching '__gnu_cxx::__alloc_traits<std::allocator<unsigned int>, unsigned int>::_Base_type {aka std::allocator_traits<std::allocator<unsigned int> >}::max_size' in '__gnu_cxx::__alloc_traits<std::allocator<unsigned int>, unsigned int>::_Base_type' {aka 'struct std::allocator_traits<std::allocator<unsigned int> >'}
   70 |     using _Base_type::max_size;
      |                       ^~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h: In instantiation of 'struct __gnu_cxx::__alloc_traits<std::allocator<long unsigned int>, long unsigned int>':
/usr/include/c++/9/bits/stl_vector.h:84:21:   required from 'struct std::_Vector_base<long unsigned int, std::allocator<long unsigned int> >'
/usr/include/c++/9/bits/stl_vector.h:386:11:   required from 'class std::vector<long unsigned int>'
/usr/include/c++/9/bits/regex_automaton.h:213:36:   required from here
/usr/include/c++/9/ext/alloc_traits.h:61:53: error: no type named 'size_type' in 'struct std::allocator_traits<std::allocator<long unsigned int> >'
   61 |     typedef typename _Base_type::size_type          size_type;
      |                                                     ^~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:62:53: error: no type named 'difference_type' in 'struct std::allocator_traits<std::allocator<long unsigned int> >'
   62 |     typedef typename _Base_type::difference_type    difference_type;
      |                                                     ^~~~~~~~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:70:23: error: no members matching '__gnu_cxx::__alloc_traits<std::allocator<long unsigned int>, long unsigned int>::_Base_type {aka std::allocator_traits<std::allocator<long unsigned int> >}::max_size' in '__gnu_cxx::__alloc_traits<std::allocator<long unsigned int>, long unsigned int>::_Base_type' {aka 'struct std::allocator_traits<std::allocator<long unsigned int> >'}
   70 |     using _Base_type::max_size;
      |                       ^~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h: In instantiation of 'struct __gnu_cxx::__alloc_traits<std::allocator<long int>, long int>':
/usr/include/c++/9/bits/stl_deque.h:483:21:   required from 'class std::_Deque_base<long int, std::allocator<long int> >'
/usr/include/c++/9/bits/stl_deque.h:849:11:   required from 'class std::deque<long int, std::allocator<long int> >'
/usr/include/c++/9/bits/stl_stack.h:134:47:   required from 'class std::stack<long int>'
/usr/include/c++/9/bits/regex_automaton.tcc:199:14:   required from here
/usr/include/c++/9/ext/alloc_traits.h:61:53: error: no type named 'size_type' in 'struct std::allocator_traits<std::allocator<long int> >'
   61 |     typedef typename _Base_type::size_type          size_type;
      |                                                     ^~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:62:53: error: no type named 'difference_type' in 'struct std::allocator_traits<std::allocator<long int> >'
   62 |     typedef typename _Base_type::difference_type    difference_type;
      |                                                     ^~~~~~~~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:70:23: error: no members matching '__gnu_cxx::__alloc_traits<std::allocator<long int>, long int>::_Base_type {aka std::allocator_traits<std::allocator<long int> >}::max_size' in '__gnu_cxx::__alloc_traits<std::allocator<long int>, long int>::_Base_type' {aka 'struct std::allocator_traits<std::allocator<long int> >'}
   70 |     using _Base_type::max_size;
      |                       ^~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h: In instantiation of 'struct __gnu_cxx::__alloc_traits<std::allocator<std::pair<const long int, long int> >, std::pair<const long int, long int> >':
/usr/include/c++/9/bits/stl_map.h:145:28:   required from 'class std::map<long int, long int>'
/usr/include/c++/9/bits/regex_automaton.tcc:207:11:   required from here
/usr/include/c++/9/ext/alloc_traits.h:61:53: error: no type named 'size_type' in 'struct std::allocator_traits<std::allocator<std::pair<const long int, long int> > >'
   61 |     typedef typename _Base_type::size_type          size_type;
      |                                                     ^~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:62:53: error: no type named 'difference_type' in 'struct std::allocator_traits<std::allocator<std::pair<const long int, long int> > >'
   62 |     typedef typename _Base_type::difference_type    difference_type;
      |                                                     ^~~~~~~~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:70:23: error: no members matching '__gnu_cxx::__alloc_traits<std::allocator<std::pair<const long int, long int> >, std::pair<const long int, long int> >::_Base_type {aka std::allocator_traits<std::allocator<std::pair<const long int, long int> > >}::max_size' in '__gnu_cxx::__alloc_traits<std::allocator<std::pair<const long int, long int> >, std::pair<const long int, long int> >::_Base_type' {aka 'struct std::allocator_traits<std::allocator<std::pair<const long int, long int> > >'}
   70 |     using _Base_type::max_size;
      |                       ^~~~~~~~
In file included from /usr/include/c++/9/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:110,
                 from foo.cc:2:
/usr/include/c++/9/bits/regex.h:169:19: error: 'size_t' in namespace 'std' does not name a type
  169 |       static std::size_t
      |                   ^~~~~~
/usr/include/c++/9/bits/regex.h:453:45: error: 'std::size_t' has not been declared
  453 |       basic_regex(const _Ch_type* __p, std::size_t __len,
      |                                             ^~~~~~
/usr/include/c++/9/bits/regex.h:632:40: error: 'std::size_t' has not been declared
  632 |       assign(const _Ch_type* __p, std::size_t __len, flag_type __flags)
      |                                        ^~~~~~
/usr/include/c++/9/bits/regex.h:2518:20: error: 'ptrdiff_t' in namespace 'std' does not name a type
 2518 |       typedef std::ptrdiff_t       difference_type;
      |                    ^~~~~~~~~
/usr/include/c++/9/bits/regex.h:2635:20: error: 'ptrdiff_t' in namespace 'std' does not name a type
 2635 |       typedef std::ptrdiff_t   difference_type;
      |                    ^~~~~~~~~
/usr/include/c++/9/bits/regex.h:2720:21: error: 'std::size_t' has not been declared
 2720 |       template<std::size_t _Nm>
      |                     ^~~~~~
/usr/include/c++/9/bits/regex.h:2723:35: error: '_Nm' was not declared in this scope
 2723 |         const int (&__submatches)[_Nm],
      |                                   ^~~
/usr/include/c++/9/bits/regex.h:2723:39: error: expected ')' before ',' token
 2723 |         const int (&__submatches)[_Nm],
      |                                       ^
      |                                       )
/usr/include/c++/9/bits/regex.h:2721:22: note: to match this '('
 2721 |  regex_token_iterator(_Bi_iter __a, _Bi_iter __b,
      |                      ^
/usr/include/c++/9/bits/regex.h:2723:39: error: expected ';' before ',' token
 2723 |         const int (&__submatches)[_Nm],
      |                                       ^
      |                                       ;
/usr/include/c++/9/bits/regex.h:2743:22: error: 'std::size_t' has not been declared
 2743 |       template <std::size_t _Nm>
      |                      ^~~~~~
/usr/include/c++/9/bits/regex.h:2745:23: error: '_Nm' was not declared in this scope
 2745 |         const int (&)[_Nm],
      |                       ^~~
/usr/include/c++/9/bits/regex.h:2745:27: error: expected ')' before ',' token
 2745 |         const int (&)[_Nm],
      |                           ^
      |                           )
/usr/include/c++/9/bits/regex.h:2744:22: note: to match this '('
 2744 |  regex_token_iterator(_Bi_iter, _Bi_iter, const regex_type&&,
      |                      ^
/usr/include/c++/9/bits/regex.h:2745:27: error: expected ';' before ',' token
 2745 |         const int (&)[_Nm],
      |                           ^
      |                           ;
/usr/include/c++/9/bits/regex.h:2744:2: error: 'template<class _Bi_iter, class _Ch_type, class _Rx_traits> template<<declaration error> > std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>::regex_token_iterator(...)' cannot be overloaded with 'template<class _Bi_iter, class _Ch_type, class _Rx_traits> template<<declaration error> > std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>::regex_token_iterator(...)'
 2744 |  regex_token_iterator(_Bi_iter, _Bi_iter, const regex_type&&,
      |  ^~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/regex.h:2721:2: note: previous declaration 'template<class _Bi_iter, class _Ch_type, class _Rx_traits> template<<declaration error> > std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>::regex_token_iterator(...)'
 2721 |  regex_token_iterator(_Bi_iter __a, _Bi_iter __b,
      |  ^~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/9/bits/basic_string.h:40,
                 from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/ext/alloc_traits.h: In instantiation of 'struct __gnu_cxx::__alloc_traits<std::allocator<int>, int>':
/usr/include/c++/9/bits/stl_vector.h:84:21:   required from 'struct std::_Vector_base<int, std::allocator<int> >'
/usr/include/c++/9/bits/stl_vector.h:386:11:   required from 'class std::vector<int>'
/usr/include/c++/9/bits/regex.h:2841:24:   required from here
/usr/include/c++/9/ext/alloc_traits.h:61:53: error: no type named 'size_type' in 'struct std::allocator_traits<std::allocator<int> >'
   61 |     typedef typename _Base_type::size_type          size_type;
      |                                                     ^~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:62:53: error: no type named 'difference_type' in 'struct std::allocator_traits<std::allocator<int> >'
   62 |     typedef typename _Base_type::difference_type    difference_type;
      |                                                     ^~~~~~~~~~~~~~~
/usr/include/c++/9/ext/alloc_traits.h:70:23: error: no members matching '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::_Base_type {aka std::allocator_traits<std::allocator<int> >}::max_size' in '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::_Base_type' {aka 'struct std::allocator_traits<std::allocator<int> >'}
   70 |     using _Base_type::max_size;
      |                       ^~~~~~~~
In file included from /usr/include/c++/9/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:110,
                 from foo.cc:2:
/usr/include/c++/9/bits/regex.h:2843:12: error: 'size_t' in namespace 'std' does not name a type
 2843 |       std::size_t _M_n;
      |            ^~~~~~
/usr/include/c++/9/bits/regex.h: In constructor 'std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>::regex_token_iterator()':
/usr/include/c++/9/bits/regex.h:2649:48: error: class 'std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>' does not have any field named '_M_n'
 2649 |       : _M_position(), _M_subs(), _M_suffix(), _M_n(0), _M_result(nullptr),
      |                                                ^~~~
/usr/include/c++/9/bits/regex.h: In constructor 'std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>::regex_token_iterator(_Bi_iter, _Bi_iter, const regex_type&, int, std::regex_constants::match_flag_type)':
/usr/include/c++/9/bits/regex.h:2674:67: error: class 'std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>' does not have any field named '_M_n'
 2674 |       : _M_position(__a, __b, __re, __m), _M_subs(1, __submatch), _M_n(0)
      |                                                                   ^~~~
/usr/include/c++/9/bits/regex.h: In constructor 'std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>::regex_token_iterator(_Bi_iter, _Bi_iter, const regex_type&, const std::vector<int>&, std::regex_constants::match_flag_type)':
/usr/include/c++/9/bits/regex.h:2691:66: error: class 'std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>' does not have any field named '_M_n'
 2691 |       : _M_position(__a, __b, __re, __m), _M_subs(__submatches), _M_n(0)
      |                                                                  ^~~~
/usr/include/c++/9/bits/regex.h: In constructor 'std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>::regex_token_iterator(_Bi_iter, _Bi_iter, const regex_type&, std::initializer_list<int>, std::regex_constants::match_flag_type)':
/usr/include/c++/9/bits/regex.h:2708:66: error: class 'std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>' does not have any field named '_M_n'
 2708 |       : _M_position(__a, __b, __re, __m), _M_subs(__submatches), _M_n(0)
      |                                                                  ^~~~
/usr/include/c++/9/bits/regex.h: In copy constructor 'std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>::regex_token_iterator(const std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>&)':
/usr/include/c++/9/bits/regex.h:2755:35: error: class 'std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>' does not have any field named '_M_n'
 2755 |       _M_suffix(__rhs._M_suffix), _M_n(__rhs._M_n), _M_has_m1(__rhs._M_has_m1)
      |                                   ^~~~
/usr/include/c++/9/bits/regex.h: In member function 'const value_type& std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>::_M_current_match() const':
/usr/include/c++/9/bits/regex.h:2818:14: error: '_M_n' was not declared in this scope
 2818 |  if (_M_subs[_M_n] == -1)
      |              ^~~~
In file included from /usr/include/c++/9/bits/regex.h:2870,
                 from /usr/include/c++/9/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:110,
                 from foo.cc:2:
/usr/include/c++/9/bits/regex.tcc: In member function 'std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>& std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>::operator=(const std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>&)':
/usr/include/c++/9/bits/regex.tcc:582:7: error: '_M_n' was not declared in this scope
  582 |       _M_n = __rhs._M_n;
      |       ^~~~
/usr/include/c++/9/bits/regex.tcc: In member function 'bool std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>::operator==(const std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>&) const':
/usr/include/c++/9/bits/regex.tcc:605:5: error: '_M_n' was not declared in this scope
  605 |  && _M_n == __rhs._M_n
      |     ^~~~
/usr/include/c++/9/bits/regex.tcc: In member function 'std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>& std::__cxx11::regex_token_iterator<_Bi_iter, _Ch_type, _Rx_traits>::operator++()':
/usr/include/c++/9/bits/regex.tcc:619:16: error: '_M_n' was not declared in this scope
  619 |       else if (_M_n + 1 < _M_subs.size())
      |                ^~~~
In file included from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:111,
                 from foo.cc:2:
/usr/include/c++/9/scoped_allocator: At global scope:
/usr/include/c++/9/scoped_allocator:233:21: error: 'std::size_t' has not been declared
  233 |       template<std::size_t... _Indices>
      |                     ^~~~~~
/usr/include/c++/9/scoped_allocator:236:47: error: '_Indices' was not declared in this scope
  236 |                                  _Index_tuple<_Indices...>)
      |                                               ^~~~~~~~
/usr/include/c++/9/scoped_allocator:236:55: error: expected parameter pack before '...'
  236 |                                  _Index_tuple<_Indices...>)
      |                                                       ^~~
/usr/include/c++/9/scoped_allocator:236:58: error: template argument 1 is invalid
  236 |                                  _Index_tuple<_Indices...>)
      |                                                          ^
/usr/include/c++/9/scoped_allocator:469:53: note: invalid template non-type parameter
  469 |  _M_construct_p(__uses_alloc1_, _Index_tuple<_Ind...>,
      |                                                     ^
/usr/include/c++/9/scoped_allocator:479:53: note: invalid template non-type parameter
  479 |  _M_construct_p(__uses_alloc2_, _Index_tuple<_Ind...>,
      |                                                     ^
/usr/include/c++/9/scoped_allocator: In constructor 'std::scoped_allocator_adaptor<_OuterAlloc, _InnerAllocs>::scoped_allocator_adaptor(std::tuple<const _OuterAlloc&, const _InnerAllocs& ...>, int)':
/usr/include/c++/9/scoped_allocator:238:47: error: '_Indices' was not declared in this scope
  238 |           _M_inner(_S_select_on_copy(std::get<_Indices+1>(__refs))...)
      |                                               ^~~~~~~~
/usr/include/c++/9/scoped_allocator:238:67: error: expansion pattern 'std::scoped_allocator_adaptor<_OuterAlloc, _InnerAllocs>::_S_select_on_copy(get<<expression error> >(__refs))' contains no parameter packs
  238 |           _M_inner(_S_select_on_copy(std::get<_Indices+1>(__refs))...)
      |                                                                   ^~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h: At global scope:
/usr/include/c++/9/bits/hashtable_policy.h:266:12: error: 'size_t' in namespace 'std' does not name a type
  266 |       std::size_t  _M_hash_code;
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:327:20: error: 'ptrdiff_t' in namespace 'std' does not name a type
  327 |       typedef std::ptrdiff_t    difference_type;
      |                    ^~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:378:20: error: 'ptrdiff_t' in namespace 'std' does not name a type
  378 |       typedef std::ptrdiff_t    difference_type;
      |                    ^~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:426:18: error: 'size_t' in namespace 'std' does not name a type
  426 |     typedef std::size_t first_argument_type;
      |                  ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:427:18: error: 'size_t' in namespace 'std' does not name a type
  427 |     typedef std::size_t second_argument_type;
      |                  ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:428:18: error: 'size_t' in namespace 'std' does not name a type
  428 |     typedef std::size_t result_type;
      |                  ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:430:5: error: 'result_type' does not name a type; did you mean 'result_of'?
  430 |     result_type
      |     ^~~~~~~~~~~
      |     result_of
/usr/include/c++/9/bits/hashtable_policy.h:457:10: error: 'size_t' in namespace 'std' does not name a type
  457 |     std::size_t
      |          ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:461:10: error: 'size_t' in namespace 'std' does not name a type
  461 |     std::size_t
      |          ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:469:26: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  469 |     std::pair<bool, std::size_t>
      |                          ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:469:26: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  469 |     std::pair<bool, std::size_t>
      |                          ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:469:32: error: template argument 2 is invalid
  469 |     std::pair<bool, std::size_t>
      |                                ^
/usr/include/c++/9/bits/hashtable_policy.h:470:25: error: 'std::size_t' has not been declared
  470 |     _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt,
      |                         ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:470:46: error: 'std::size_t' has not been declared
  470 |     _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt,
      |                                              ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:471:11: error: 'std::size_t' has not been declared
  471 |      std::size_t __n_ins) const;
      |           ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:473:18: error: 'size_t' in namespace 'std' does not name a type
  473 |     typedef std::size_t _State;
      |                  ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:475:5: error: invalid use of template-name 'std::__detail::_State' without an argument list
  475 |     _State
      |     ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:475:5: note: class template argument deduction is only available with '-std=c++17' or '-std=gnu++17'
In file included from /usr/include/c++/9/regex:59,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:110,
                 from foo.cc:2:
/usr/include/c++/9/bits/regex_automaton.h:122:12: note: 'template<class _Char_type> struct std::__detail::_State' declared here
  122 |     struct _State : _State_base
      |            ^~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:484:14: error: '_State' is not a type
  484 |     _M_reset(_State __state)
      |              ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:487:23: error: 'size_t' in namespace 'std' does not name a type
  487 |     static const std::size_t _S_growth_factor = 2;
      |                       ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:490:18: error: 'size_t' in namespace 'std' does not name a type
  490 |     mutable std::size_t _M_next_resize;
      |                  ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In constructor 'std::__detail::_Prime_rehash_policy::_Prime_rehash_policy(float)':
/usr/include/c++/9/bits/hashtable_policy.h:450:32: error: class 'std::__detail::_Prime_rehash_policy' does not have any field named '_M_next_resize'
  450 |     : _M_max_load_factor(__z), _M_next_resize(0) { }
      |                                ^~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In member function 'void std::__detail::_Prime_rehash_policy::_M_reset()':
/usr/include/c++/9/bits/hashtable_policy.h:481:7: error: '_M_next_resize' was not declared in this scope
  481 |     { _M_next_resize = 0; }
      |       ^~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In member function 'void std::__detail::_Prime_rehash_policy::_M_reset(int)':
/usr/include/c++/9/bits/hashtable_policy.h:485:7: error: '_M_next_resize' was not declared in this scope
  485 |     { _M_next_resize = __state; }
      |       ^~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: At global scope:
/usr/include/c++/9/bits/hashtable_policy.h:496:18: error: 'size_t' in namespace 'std' does not name a type
  496 |     typedef std::size_t first_argument_type;
      |                  ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:497:18: error: 'size_t' in namespace 'std' does not name a type
  497 |     typedef std::size_t second_argument_type;
      |                  ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:498:18: error: 'size_t' in namespace 'std' does not name a type
  498 |     typedef std::size_t result_type;
      |                  ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:500:5: error: 'result_type' does not name a type; did you mean 'result_of'?
  500 |     result_type
      |     ^~~~~~~~~~~
      |     result_of
/usr/include/c++/9/bits/hashtable_policy.h:507:15: error: 'size_t' in namespace 'std' does not name a type
  507 |   inline std::size_t
      |               ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:535:10: error: 'size_t' in namespace 'std' does not name a type
  535 |     std::size_t
      |          ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:561:10: error: 'size_t' in namespace 'std' does not name a type
  561 |     std::size_t
      |          ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:569:26: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  569 |     std::pair<bool, std::size_t>
      |                          ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:569:26: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  569 |     std::pair<bool, std::size_t>
      |                          ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:569:32: error: template argument 2 is invalid
  569 |     std::pair<bool, std::size_t>
      |                                ^
/usr/include/c++/9/bits/hashtable_policy.h:570:25: error: 'std::size_t' has not been declared
  570 |     _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt,
      |                         ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:570:46: error: 'std::size_t' has not been declared
  570 |     _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt,
      |                                              ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:571:11: error: 'std::size_t' has not been declared
  571 |      std::size_t __n_ins) noexcept
      |           ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:590:18: error: 'size_t' in namespace 'std' does not name a type
  590 |     typedef std::size_t _State;
      |                  ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:592:5: error: invalid use of template-name 'std::__detail::_State' without an argument list
  592 |     _State
      |     ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:592:5: note: class template argument deduction is only available with '-std=c++17' or '-std=gnu++17'
In file included from /usr/include/c++/9/regex:59,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:110,
                 from foo.cc:2:
/usr/include/c++/9/bits/regex_automaton.h:122:12: note: 'template<class _Char_type> struct std::__detail::_State' declared here
  122 |     struct _State : _State_base
      |            ^~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:601:14: error: '_State' is not a type
  601 |     _M_reset(_State __state) noexcept
      |              ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:604:23: error: 'size_t' in namespace 'std' does not name a type
  604 |     static const std::size_t _S_growth_factor = 2;
      |                       ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:607:10: error: 'size_t' in namespace 'std' does not name a type
  607 |     std::size_t _M_next_resize;
      |          ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In constructor 'std::__detail::_Power2_rehash_policy::_Power2_rehash_policy(float)':
/usr/include/c++/9/bits/hashtable_policy.h:527:32: error: class 'std::__detail::_Power2_rehash_policy' does not have any field named '_M_next_resize'
  527 |     : _M_max_load_factor(__z), _M_next_resize(0) { }
      |                                ^~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In member function 'int std::__detail::_Power2_rehash_policy::_M_need_rehash(int, int, int)':
/usr/include/c++/9/bits/hashtable_policy.h:573:32: error: '_M_next_resize' was not declared in this scope
  573 |       if (__n_elt + __n_ins >= _M_next_resize)
      |                                ^~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:579:34: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  579 |        _M_next_bkt(std::max<std::size_t>(__builtin_floor(__min_bkts) + 1,
      |                                  ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:579:34: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  579 |        _M_next_bkt(std::max<std::size_t>(__builtin_floor(__min_bkts) + 1,
      |                                  ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:580:17: error: '_S_growth_factor' was not declared in this scope
  580 |       __n_bkt * _S_growth_factor)));
      |                 ^~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:579:8: error: '_M_next_bkt' was not declared in this scope; did you mean '__n_bkt'?
  579 |        _M_next_bkt(std::max<std::size_t>(__builtin_floor(__min_bkts) + 1,
      |        ^~~~~~~~~~~
      |        __n_bkt
/usr/include/c++/9/bits/hashtable_policy.h:584:25: error: cannot convert 'std::pair<bool, int>' to 'int' in return
  584 |    return std::make_pair(false, 0);
      |           ~~~~~~~~~~~~~~^~~~~~~~~~
      |                         |
      |                         std::pair<bool, int>
/usr/include/c++/9/bits/hashtable_policy.h:587:23: error: cannot convert 'std::pair<bool, int>' to 'int' in return
  587 |  return std::make_pair(false, 0);
      |         ~~~~~~~~~~~~~~^~~~~~~~~~
      |                       |
      |                       std::pair<bool, int>
/usr/include/c++/9/bits/hashtable_policy.h: In member function 'void std::__detail::_Power2_rehash_policy::_M_reset()':
/usr/include/c++/9/bits/hashtable_policy.h:598:7: error: '_M_next_resize' was not declared in this scope
  598 |     { _M_next_resize = 0; }
      |       ^~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In member function 'void std::__detail::_Power2_rehash_policy::_M_reset(int)':
/usr/include/c++/9/bits/hashtable_policy.h:602:7: error: '_M_next_resize' was not declared in this scope
  602 |     { _M_next_resize = __state; }
      |       ^~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: At global scope:
/usr/include/c++/9/bits/hashtable_policy.h:670:7: error: 'mapped_type' does not name a type
  670 |       mapped_type&
      |       ^~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:673:7: error: 'mapped_type' does not name a type
  673 |       mapped_type&
      |       ^~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:678:7: error: 'mapped_type' does not name a type
  678 |       mapped_type&
      |       ^~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:681:13: error: 'mapped_type' does not name a type
  681 |       const mapped_type&
      |             ^~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:692:8: error: 'mapped_type' does not name a type
  692 |     -> mapped_type&
      |        ^~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:692:19: error: expected initializer before '&' token
  692 |     -> mapped_type&
      |                   ^
/usr/include/c++/9/bits/hashtable_policy.h:717:8: error: 'mapped_type' does not name a type
  717 |     -> mapped_type&
      |        ^~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:717:19: error: expected initializer before '&' token
  717 |     -> mapped_type&
      |                   ^
/usr/include/c++/9/bits/hashtable_policy.h:742:8: error: 'mapped_type' does not name a type
  742 |     -> mapped_type&
      |        ^~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:742:19: error: expected initializer before '&' token
  742 |     -> mapped_type&
      |                   ^
/usr/include/c++/9/bits/hashtable_policy.h:761:14: error: expected initializer before 'mapped_type'
  761 |     -> const mapped_type&
      |              ^~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In member function 'void std::__detail::_Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::_M_insert_range(_InputIterator, _InputIterator, const _NodeGetter&, std::false_type)':
/usr/include/c++/9/bits/hashtable_policy.h:888:41: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  888 |  using pair_type = std::pair<bool, std::size_t>;
      |                                         ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:888:41: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  888 |  using pair_type = std::pair<bool, std::size_t>;
      |                                         ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:888:47: error: template argument 2 is invalid
  888 |  using pair_type = std::pair<bool, std::size_t>;
      |                                               ^
/usr/include/c++/9/bits/hashtable_policy.h:897:2: error: 'pair_type' was not declared in this scope
  897 |  pair_type __do_rehash = __rehash._M_need_rehash(__h._M_bucket_count,
      |  ^~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:901:6: error: '__do_rehash' was not declared in this scope; did you mean '__rehash'?
  901 |  if (__do_rehash.first)
      |      ^~~~~~~~~~~
      |      __rehash
/usr/include/c++/9/bits/hashtable_policy.h: At global scope:
/usr/include/c++/9/bits/hashtable_policy.h:1074:20: error: 'std::size_t' has not been declared
 1074 |       reserve(std::size_t __n)
      |                    ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1199:12: error: 'size_t' in namespace 'std' does not name a type
 1199 |       std::size_t
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1203:12: error: 'size_t' in namespace 'std' does not name a type
 1203 |       std::size_t
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1275:20: error: 'size_t' in namespace 'std' does not name a type
 1275 |       typedef std::size_t     __hash_code;
      |                    ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1287:7: error: '__hash_code' does not name a type; did you mean '_Hash_node'?
 1287 |       __hash_code
      |       ^~~~~~~~~~~
      |       _Hash_node
/usr/include/c++/9/bits/hashtable_policy.h:1295:12: error: 'size_t' in namespace 'std' does not name a type
 1295 |       std::size_t
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1299:12: error: 'size_t' in namespace 'std' does not name a type
 1299 |       std::size_t
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1307:35: error: '__hash_code' has not been declared
 1307 |       _M_store_code(__node_type*, __hash_code) const
      |                                   ^~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1369:20: error: 'size_t' in namespace 'std' does not name a type
 1369 |       typedef std::size_t     __hash_code;
      |                    ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1379:7: error: '__hash_code' does not name a type; did you mean '_Hash_node'?
 1379 |       __hash_code
      |       ^~~~~~~~~~~
      |       _Hash_node
/usr/include/c++/9/bits/hashtable_policy.h:1387:12: error: 'size_t' in namespace 'std' does not name a type
 1387 |       std::size_t
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1392:12: error: 'size_t' in namespace 'std' does not name a type
 1392 |       std::size_t
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1399:39: error: '__hash_code' has not been declared
 1399 |       _M_store_code(__node_type* __n, __hash_code __c) const
      |                                       ^~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1480:12: error: 'std::size_t' has not been declared
 1480 |       std::size_t __bkt, std::size_t __bkt_count)
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1480:31: error: 'std::size_t' has not been declared
 1480 |       std::size_t __bkt, std::size_t __bkt_count)
      |                               ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1499:12: error: 'size_t' in namespace 'std' does not name a type
 1499 |       std::size_t _M_bucket;
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1500:12: error: 'size_t' in namespace 'std' does not name a type
 1500 |       std::size_t _M_bucket_count;
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1506:12: error: 'size_t' in namespace 'std' does not name a type
 1506 |       std::size_t
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In constructor 'std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, true>::_Local_iterator_base(const __hash_code_base&, std::__detail::_Hash_node<_Value, true>*, int, int)':
/usr/include/c++/9/bits/hashtable_policy.h:1482:15: error: class 'std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, true>' does not have any field named '_M_bucket'
 1482 |  _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) { }
      |               ^~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1482:33: error: class 'std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, true>' does not have any field named '_M_bucket_count'
 1482 |  _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) { }
      |                                 ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In member function 'void std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, true>::_M_incr()':
/usr/include/c++/9/bits/hashtable_policy.h:1490:11: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1490 |      std::size_t __bkt
      |           ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:1493:10: error: '__bkt' was not declared in this scope; did you mean '__cbrt'?
 1493 |      if (__bkt != _M_bucket)
      |          ^~~~~
      |          __cbrt
/usr/include/c++/9/bits/hashtable_policy.h:1493:19: error: '_M_bucket' was not declared in this scope
 1493 |      if (__bkt != _M_bucket)
      |                   ^~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: At global scope:
/usr/include/c++/9/bits/hashtable_policy.h:1562:12: error: 'std::size_t' has not been declared
 1562 |       std::size_t __bkt, std::size_t __bkt_count)
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1562:31: error: 'std::size_t' has not been declared
 1562 |       std::size_t __bkt, std::size_t __bkt_count)
      |                               ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1607:12: error: 'size_t' in namespace 'std' does not name a type
 1607 |       std::size_t _M_bucket;
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1608:12: error: 'size_t' in namespace 'std' does not name a type
 1608 |       std::size_t _M_bucket_count;
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1621:12: error: 'size_t' in namespace 'std' does not name a type
 1621 |       std::size_t
      |            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In constructor 'std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>::_Local_iterator_base()':
/usr/include/c++/9/bits/hashtable_policy.h:1558:32: error: class 'std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>' does not have any field named '_M_bucket_count'
 1558 |       _Local_iterator_base() : _M_bucket_count(-1) { }
      |                                ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In constructor 'std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>::_Local_iterator_base(const __hash_code_base&, std::__detail::_Hash_node<_Value, false>*, int, int)':
/usr/include/c++/9/bits/hashtable_policy.h:1563:22: error: class 'std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>' does not have any field named '_M_bucket'
 1563 |       : _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count)
      |                      ^~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1563:40: error: class 'std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>' does not have any field named '_M_bucket_count'
 1563 |       : _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count)
      |                                        ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In destructor 'std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>::~_Local_iterator_base()':
/usr/include/c++/9/bits/hashtable_policy.h:1568:6: error: '_M_bucket_count' was not declared in this scope
 1568 |  if (_M_bucket_count != -1)
      |      ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In copy constructor 'std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>::_Local_iterator_base(const std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>&)':
/usr/include/c++/9/bits/hashtable_policy.h:1573:32: error: class 'std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>' does not have any field named '_M_bucket'
 1573 |       : _M_cur(__iter._M_cur), _M_bucket(__iter._M_bucket),
      |                                ^~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1574:9: error: class 'std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>' does not have any field named '_M_bucket_count'
 1574 |         _M_bucket_count(__iter._M_bucket_count)
      |         ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1576:6: error: '_M_bucket_count' was not declared in this scope
 1576 |  if (_M_bucket_count != -1)
      |      ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In member function 'std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>& std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>::operator=(const std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>&)':
/usr/include/c++/9/bits/hashtable_policy.h:1583:6: error: '_M_bucket_count' was not declared in this scope
 1583 |  if (_M_bucket_count != -1)
      |      ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1586:2: error: '_M_bucket' was not declared in this scope
 1586 |  _M_bucket = __iter._M_bucket;
      |  ^~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1587:2: error: '_M_bucket_count' was not declared in this scope
 1587 |  _M_bucket_count = __iter._M_bucket_count;
      |  ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In member function 'void std::__detail::_Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>::_M_incr()':
/usr/include/c++/9/bits/hashtable_policy.h:1599:11: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1599 |      std::size_t __bkt = this->_M_h()->_M_bucket_index(_M_cur,
      |           ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:1601:10: error: '__bkt' was not declared in this scope; did you mean '__cbrt'?
 1601 |      if (__bkt != _M_bucket)
      |          ^~~~~
      |          __cbrt
/usr/include/c++/9/bits/hashtable_policy.h:1601:19: error: '_M_bucket' was not declared in this scope
 1601 |      if (__bkt != _M_bucket)
      |                   ^~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: At global scope:
/usr/include/c++/9/bits/hashtable_policy.h:1663:20: error: 'ptrdiff_t' in namespace 'std' does not name a type
 1663 |       typedef std::ptrdiff_t    difference_type;
      |                    ^~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1670:14: error: 'std::size_t' has not been declared
 1670 |         std::size_t __bkt, std::size_t __bkt_count)
      |              ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1670:33: error: 'std::size_t' has not been declared
 1670 |         std::size_t __bkt, std::size_t __bkt_count)
      |                                 ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1715:20: error: 'ptrdiff_t' in namespace 'std' does not name a type
 1715 |       typedef std::ptrdiff_t    difference_type;
      |                    ^~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1722:13: error: 'std::size_t' has not been declared
 1722 |        std::size_t __bkt, std::size_t __bkt_count)
      |             ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1722:32: error: 'std::size_t' has not been declared
 1722 |        std::size_t __bkt, std::size_t __bkt_count)
      |                                ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1779:18: error: 'size_t' in namespace 'std' does not name a type
 1779 |     typedef std::size_t     size_type;
      |                  ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:1780:18: error: 'ptrdiff_t' in namespace 'std' does not name a type
 1780 |     typedef std::ptrdiff_t    difference_type;
      |                  ^~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h: In static member function 'static bool std::__detail::_Equality_base::_S_is_permutation(_Uiterator, _Uiterator, _Uiterator)':
/usr/include/c++/9/bits/hashtable_policy.h:1892:9: error: 'ptrdiff_t' is not a member of 'std'; did you mean 'ptrdiff_t'?
 1892 |    std::ptrdiff_t __n2 = 0;
      |         ^~~~~~~~~
In file included from /usr/include/c++/9/cstddef:50,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:45,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:143:26: note: 'ptrdiff_t' declared here
  143 | typedef __PTRDIFF_TYPE__ ptrdiff_t;
      |                          ^~~~~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:1895:10: error: '__n2' was not declared in this scope
 1895 |        ++__n2;
      |          ^~~~
/usr/include/c++/9/bits/hashtable_policy.h:1897:9: error: '__n2' was not declared in this scope
 1897 |    if (!__n2)
      |         ^~~~
/usr/include/c++/9/bits/hashtable_policy.h:1900:9: error: 'ptrdiff_t' is not a member of 'std'; did you mean 'ptrdiff_t'?
 1900 |    std::ptrdiff_t __n1 = 0;
      |         ^~~~~~~~~
In file included from /usr/include/c++/9/cstddef:50,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:45,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:143:26: note: 'ptrdiff_t' declared here
  143 | typedef __PTRDIFF_TYPE__ ptrdiff_t;
      |                          ^~~~~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:1903:10: error: '__n1' was not declared in this scope; did you mean '__y1'?
 1903 |        ++__n1;
      |          ^~~~
      |          __y1
/usr/include/c++/9/bits/hashtable_policy.h:1905:8: error: '__n1' was not declared in this scope; did you mean '__y1'?
 1905 |    if (__n1 != __n2)
      |        ^~~~
      |        __y1
/usr/include/c++/9/bits/hashtable_policy.h:1905:16: error: '__n2' was not declared in this scope
 1905 |    if (__n1 != __n2)
      |                ^~~~
/usr/include/c++/9/bits/hashtable_policy.h: At global scope:
/usr/include/c++/9/bits/hashtable_policy.h:2068:7: error: expected ';' at end of member declaration
 2068 |       _M_allocate_buckets(std::size_t __n);
      |       ^~~~~~~~~~~~~~~~~~~
      |                          ;
/usr/include/c++/9/bits/hashtable_policy.h:2068:38: error: expected ')' before '__n'
 2068 |       _M_allocate_buckets(std::size_t __n);
      |                          ~           ^~~~
      |                                      )
/usr/include/c++/9/bits/hashtable_policy.h:2071:50: error: 'std::size_t' has not been declared
 2071 |       _M_deallocate_buckets(__bucket_type*, std::size_t __n);
      |                                                  ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:2130:5: error: 'std::__detail::_Hashtable_alloc<_NodeAlloc>::__node_base** std::__detail::_Hashtable_alloc<_NodeAlloc>::_M_allocate_buckets' is not a static data member of 'struct std::__detail::_Hashtable_alloc<_NodeAlloc>'
 2130 |     _Hashtable_alloc<_NodeAlloc>::_M_allocate_buckets(std::size_t __n)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:2130:60: error: template definition of non-template 'std::__detail::_Hashtable_alloc<_NodeAlloc>::__node_base** std::__detail::_Hashtable_alloc<_NodeAlloc>::_M_allocate_buckets'
 2130 |     _Hashtable_alloc<_NodeAlloc>::_M_allocate_buckets(std::size_t __n)
      |                                                            ^~~~~~
/usr/include/c++/9/bits/hashtable_policy.h:2130:60: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/bits/hashtable.h:35,
                 from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable_policy.h:2143:13: error: 'std::size_t' has not been declared
 2143 |        std::size_t __n)
      |             ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:277:18: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
  277 |            (std::size_t)0)),
      |                  ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h: In member function 'void std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::_M_assign_elements(_Ht&&, const _NodeGenerator&)':
/usr/include/c++/9/bits/hashtable.h:1095:7: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1095 |  std::size_t __former_bucket_count = _M_bucket_count;
      |       ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1119:48: error: '__former_bucket_count' was not declared in this scope; did you mean '__former_buckets'?
 1119 |        _M_deallocate_buckets(__former_buckets, __former_bucket_count);
      |                                                ^~~~~~~~~~~~~~~~~~~~~
      |                                                __former_buckets
/usr/include/c++/9/bits/hashtable.h:1129:21: error: '__former_bucket_count' was not declared in this scope; did you mean '__former_buckets'?
 1129 |   _M_bucket_count = __former_bucket_count;
      |                     ^~~~~~~~~~~~~~~~~~~~~
      |                     __former_buckets
/usr/include/c++/9/bits/hashtable.h: In member function 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::iterator std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::find(const key_type&)':
/usr/include/c++/9/bits/hashtable.h:1453:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1453 |       std::size_t __n = _M_bucket_index(__k, __code);
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1454:39: error: '__n' was not declared in this scope; did you mean '__yn'?
 1454 |       __node_type* __p = _M_find_node(__n, __k, __code);
      |                                       ^~~
      |                                       __yn
/usr/include/c++/9/bits/hashtable.h: In member function 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::const_iterator std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::find(const key_type&) const':
/usr/include/c++/9/bits/hashtable.h:1469:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1469 |       std::size_t __n = _M_bucket_index(__k, __code);
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1470:39: error: '__n' was not declared in this scope; did you mean '__yn'?
 1470 |       __node_type* __p = _M_find_node(__n, __k, __code);
      |                                       ^~~
      |                                       __yn
/usr/include/c++/9/bits/hashtable.h: In member function 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::size_type std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::count(const key_type&) const':
/usr/include/c++/9/bits/hashtable.h:1485:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1485 |       std::size_t __n = _M_bucket_index(__k, __code);
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1486:42: error: '__n' was not declared in this scope; did you mean '__yn'?
 1486 |       __node_type* __p = _M_bucket_begin(__n);
      |                                          ^~~
      |                                          __yn
/usr/include/c++/9/bits/hashtable.h:1490:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1490 |       std::size_t __result = 0;
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1494:8: error: '__result' was not declared in this scope
 1494 |      ++__result;
      |        ^~~~~~~~
/usr/include/c++/9/bits/hashtable.h:1495:13: error: '__result' was not declared in this scope
 1495 |    else if (__result)
      |             ^~~~~~~~
/usr/include/c++/9/bits/hashtable.h:1503:14: error: '__result' was not declared in this scope
 1503 |       return __result;
      |              ^~~~~~~~
/usr/include/c++/9/bits/hashtable.h: In member function 'std::pair<typename std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, _Hash, _Traits>::iterator, typename std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, _Hash, _Traits>::iterator> std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::equal_range(const key_type&)':
/usr/include/c++/9/bits/hashtable.h:1517:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1517 |       std::size_t __n = _M_bucket_index(__k, __code);
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1518:39: error: '__n' was not declared in this scope; did you mean '__yn'?
 1518 |       __node_type* __p = _M_find_node(__n, __k, __code);
      |                                       ^~~
      |                                       __yn
/usr/include/c++/9/bits/hashtable.h: In member function 'std::pair<typename std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, _Hash, _Traits>::const_iterator, typename std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, _Hash, _Traits>::const_iterator> std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::equal_range(const key_type&) const':
/usr/include/c++/9/bits/hashtable.h:1544:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1544 |       std::size_t __n = _M_bucket_index(__k, __code);
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1545:39: error: '__n' was not declared in this scope; did you mean '__yn'?
 1545 |       __node_type* __p = _M_find_node(__n, __k, __code);
      |                                       ^~~
      |                                       __yn
/usr/include/c++/9/bits/hashtable.h: In member function 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::iterator std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::_M_insert_unique_node(std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::size_type, std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::__hash_code, std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::__node_type*, std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::size_type)':
/usr/include/c++/9/bits/hashtable.h:1740:28: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1740 |       std::pair<bool, std::size_t> __do_rehash
      |                            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1740:28: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1740 |       std::pair<bool, std::size_t> __do_rehash
      |                            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1740:34: error: template argument 2 is invalid
 1740 |       std::pair<bool, std::size_t> __do_rehash
      |                                  ^
/usr/include/c++/9/bits/hashtable.h:1746:20: error: request for member 'first' in '__do_rehash', which is of non-class type 'int'
 1746 |    if (__do_rehash.first)
      |                    ^~~~~
/usr/include/c++/9/bits/hashtable.h:1748:30: error: request for member 'second' in '__do_rehash', which is of non-class type 'int'
 1748 |        _M_rehash(__do_rehash.second, __saved_state);
      |                              ^~~~~~
/usr/include/c++/9/bits/hashtable.h: In member function 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::iterator std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::_M_insert_multi_node(std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::__node_type*, std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::__hash_code, std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::__node_type*)':
/usr/include/c++/9/bits/hashtable.h:1780:28: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1780 |       std::pair<bool, std::size_t> __do_rehash
      |                            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1780:28: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1780 |       std::pair<bool, std::size_t> __do_rehash
      |                            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1780:34: error: template argument 2 is invalid
 1780 |       std::pair<bool, std::size_t> __do_rehash
      |                                  ^
/usr/include/c++/9/bits/hashtable.h:1785:20: error: request for member 'first' in '__do_rehash', which is of non-class type 'int'
 1785 |    if (__do_rehash.first)
      |                    ^~~~~
/usr/include/c++/9/bits/hashtable.h:1786:28: error: request for member 'second' in '__do_rehash', which is of non-class type 'int'
 1786 |      _M_rehash(__do_rehash.second, __saved_state);
      |                            ^~~~~~
/usr/include/c++/9/bits/hashtable.h: In member function 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::iterator std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::erase(std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::const_iterator)':
/usr/include/c++/9/bits/hashtable.h:1890:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1890 |       std::size_t __bkt = _M_bucket_index(__n);
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1895:52: error: '__bkt' was not declared in this scope; did you mean '__cbrt'?
 1895 |       __node_base* __prev_n = _M_get_previous_node(__bkt, __n);
      |                                                    ^~~~~
      |                                                    __cbrt
/usr/include/c++/9/bits/hashtable.h: In member function 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::size_type std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::_M_erase(std::true_type, const key_type&)':
/usr/include/c++/9/bits/hashtable.h:1938:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1938 |       std::size_t __bkt = _M_bucket_index(__k, __code);
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1941:51: error: '__bkt' was not declared in this scope; did you mean '__cbrt'?
 1941 |       __node_base* __prev_n = _M_find_before_node(__bkt, __k, __code);
      |                                                   ^~~~~
      |                                                   __cbrt
/usr/include/c++/9/bits/hashtable.h: In member function 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::size_type std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::_M_erase(std::false_type, const key_type&)':
/usr/include/c++/9/bits/hashtable.h:1962:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1962 |       std::size_t __bkt = _M_bucket_index(__k, __code);
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1965:51: error: '__bkt' was not declared in this scope; did you mean '__cbrt'?
 1965 |       __node_base* __prev_n = _M_find_before_node(__bkt, __k, __code);
      |                                                   ^~~~~
      |                                                   __cbrt
/usr/include/c++/9/bits/hashtable.h:1977:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 1977 |       std::size_t __n_last_bkt = __bkt;
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:1983:4: error: '__n_last_bkt' was not declared in this scope; did you mean '__n_last'?
 1983 |    __n_last_bkt = _M_bucket_index(__n_last);
      |    ^~~~~~~~~~~~
      |    __n_last
/usr/include/c++/9/bits/hashtable.h:1985:14: error: '__n_last_bkt' was not declared in this scope; did you mean '__n_last'?
 1985 |       while (__n_last_bkt == __bkt && this->_M_equals(__k, __code, __n_last));
      |              ^~~~~~~~~~~~
      |              __n_last
/usr/include/c++/9/bits/hashtable.h: In member function 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::iterator std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::erase(std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::const_iterator, std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::const_iterator)':
/usr/include/c++/9/bits/hashtable.h:2022:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 2022 |       std::size_t __bkt = _M_bucket_index(__n);
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:2024:52: error: '__bkt' was not declared in this scope; did you mean '__cbrt'?
 2024 |       __node_base* __prev_n = _M_get_previous_node(__bkt, __n);
      |                                                    ^~~~~
      |                                                    __cbrt
/usr/include/c++/9/bits/hashtable.h:2026:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 2026 |       std::size_t __n_bkt = __bkt;
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:2037:8: error: '__n_bkt' was not declared in this scope
 2037 |        __n_bkt = _M_bucket_index(__n);
      |        ^~~~~~~
/usr/include/c++/9/bits/hashtable.h:2039:30: error: '__n_bkt' was not declared in this scope
 2039 |    while (__n != __last_n && __n_bkt == __bkt);
      |                              ^~~~~~~
/usr/include/c++/9/bits/hashtable.h:2048:19: error: '__n_bkt' was not declared in this scope
 2048 |       if (__n && (__n_bkt != __bkt || __is_bucket_begin))
      |                   ^~~~~~~
/usr/include/c++/9/bits/hashtable.h: In member function 'void std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::rehash(std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::size_type)':
/usr/include/c++/9/bits/hashtable.h:2079:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 2079 |       std::size_t __buckets
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:2082:7: error: '__buckets' was not declared in this scope; did you mean '_M_buckets'?
 2082 |       __buckets = _M_rehash_policy._M_next_bkt(__buckets);
      |       ^~~~~~~~~
      |       _M_buckets
/usr/include/c++/9/bits/hashtable.h: In member function 'void std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::_M_rehash_aux(std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::size_type, std::true_type)':
/usr/include/c++/9/bits/hashtable.h:2126:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 2126 |       std::size_t __bbegin_bkt = 0;
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:2130:9: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 2130 |    std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __n);
      |         ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:2131:23: error: '__bkt' was not declared in this scope; did you mean '__cbrt'?
 2131 |    if (!__new_buckets[__bkt])
      |                       ^~~~~
      |                       __cbrt
/usr/include/c++/9/bits/hashtable.h:2137:17: error: '__bbegin_bkt' was not declared in this scope
 2137 |   __new_buckets[__bbegin_bkt] = __p;
      |                 ^~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable.h:2138:8: error: '__bbegin_bkt' was not declared in this scope
 2138 |        __bbegin_bkt = __bkt;
      |        ^~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable.h: In member function 'void std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::_M_rehash_aux(std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::size_type, std::false_type)':
/usr/include/c++/9/bits/hashtable.h:2168:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 2168 |       std::size_t __bbegin_bkt = 0;
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:2169:12: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 2169 |       std::size_t __prev_bkt = 0;
      |            ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:2176:9: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 2176 |    std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __n);
      |         ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:2178:20: error: '__prev_bkt' was not declared in this scope; did you mean '__prev_p'?
 2178 |    if (__prev_p && __prev_bkt == __bkt)
      |                    ^~~~~~~~~~
      |                    __prev_p
/usr/include/c++/9/bits/hashtable.h:2178:34: error: '__bkt' was not declared in this scope; did you mean '__cbrt'?
 2178 |    if (__prev_p && __prev_bkt == __bkt)
      |                                  ^~~~~
      |                                  __cbrt
/usr/include/c++/9/bits/hashtable.h:2201:14: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 2201 |         std::size_t __next_bkt
      |              ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:2204:13: error: '__next_bkt' was not declared in this scope
 2204 |         if (__next_bkt != __prev_bkt)
      |             ^~~~~~~~~~
/usr/include/c++/9/bits/hashtable.h:2216:21: error: '__bbegin_bkt' was not declared in this scope
 2216 |       __new_buckets[__bbegin_bkt] = __p;
      |                     ^~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable.h:2217:5: error: '__bbegin_bkt' was not declared in this scope
 2217 |     __bbegin_bkt = __bkt;
      |     ^~~~~~~~~~~~
/usr/include/c++/9/bits/hashtable.h:2226:4: error: '__prev_bkt' was not declared in this scope; did you mean '__prev_p'?
 2226 |    __prev_bkt = __bkt;
      |    ^~~~~~~~~~
      |    __prev_p
/usr/include/c++/9/bits/hashtable.h:2226:17: error: '__bkt' was not declared in this scope; did you mean '__cbrt'?
 2226 |    __prev_bkt = __bkt;
      |                 ^~~~~
      |                 __cbrt
/usr/include/c++/9/bits/hashtable.h:2232:9: error: 'size_t' is not a member of 'std'; did you mean 'size_t'?
 2232 |    std::size_t __next_bkt
      |         ^~~~~~
In file included from /usr/include/stdlib.h:31,
                 from /usr/include/c++/9/bits/std_abs.h:38,
                 from /usr/include/c++/9/cmath:47,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:41,
                 from foo.cc:2:
/usr/lib/gcc/x86_64-linux-gnu/9/include/stddef.h:209:23: note: 'size_t' declared here
  209 | typedef __SIZE_TYPE__ size_t;
      |                       ^~~~~~
In file included from /usr/include/c++/9/unordered_map:46,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:117,
                 from foo.cc:2:
/usr/include/c++/9/bits/hashtable.h:2234:8: error: '__next_bkt' was not declared in this scope
 2234 |    if (__next_bkt != __prev_bkt)
      |        ^~~~~~~~~~
/usr/include/c++/9/bits/hashtable.h:2234:22: error: '__prev_bkt' was not declared in this scope; did you mean '__prev_p'?
 2234 |    if (__next_bkt != __prev_bkt)
      |                      ^~~~~~~~~~
      |                      __prev_p
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h: In instantiation of 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]':
/usr/include/c++/9/system_error:189:40:   required from here
/usr/include/c++/9/bits/basic_string.h:567:24: error: 'class std::__cxx11::basic_string<char>' has no member named '_M_allocated_capacity'; did you mean '_S_local_capacity'?
  567 |      _M_capacity(__str._M_allocated_capacity);
      |                  ~~~~~~^~~~~~~~~~~~~~~~~~~~~
      |                  _S_local_capacity
/usr/include/c++/9/bits/basic_string.h: In instantiation of 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]':
/usr/include/c++/9/system_error:351:50:   required from here
/usr/include/c++/9/bits/basic_string.h:6103:33: error: 'class std::__cxx11::basic_string<char>' has no member named 'size'
 6103 |       const auto __size = __lhs.size() + __rhs.size();
      |                           ~~~~~~^~~~
/usr/include/c++/9/bits/basic_string.h:6103:48: error: 'class std::__cxx11::basic_string<char>' has no member named 'size'
 6103 |       const auto __size = __lhs.size() + __rhs.size();
      |                                          ~~~~~~^~~~
/usr/include/c++/9/bits/basic_string.h:6104:43: error: 'class std::__cxx11::basic_string<char>' has no member named 'capacity'
 6104 |       const bool __cond = (__size > __lhs.capacity()
      |                                     ~~~~~~^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6105:26: error: 'class std::__cxx11::basic_string<char>' has no member named 'capacity'
 6105 |       && __size <= __rhs.capacity());
      |                    ~~~~~~^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6106:32: error: no matching function for call to 'std::__cxx11::basic_string<char>::insert(int, std::__cxx11::basic_string<char>&)'
 6106 |       return __cond ? std::move(__rhs.insert(0, __lhs))
      |                       ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/basic_string.h:1582:9: note: candidate: 'template<class _InputIterator, class> std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::iterator std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::insert(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::const_iterator, _InputIterator, _InputIterator) [with _InputIterator = _InputIterator; <template-parameter-2-2> = <template-parameter-1-2>; _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]'
 1582 |         insert(const_iterator __p, _InputIterator __beg, _InputIterator __end)
      |         ^~~~~~
/usr/include/c++/9/bits/basic_string.h:1582:9: note:   template argument deduction/substitution failed:
/usr/include/c++/9/bits/basic_string.h:6106:32: note:   candidate expects 3 arguments, 2 provided
 6106 |       return __cond ? std::move(__rhs.insert(0, __lhs))
      |                       ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/basic_string.h:1616:7: note: candidate: 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::iterator std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::insert(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::const_iterator, std::initializer_list<_Tp>) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::iterator = __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >; typename __gnu_cxx::__alloc_traits<typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_CharT>::other>::pointer = char*; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::const_iterator = __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >; typename __gnu_cxx::__alloc_traits<typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_CharT>::other>::const_pointer = const char*]'
 1616 |       insert(const_iterator __p, initializer_list<_CharT> __l)
      |       ^~~~~~
/usr/include/c++/9/bits/basic_string.h:1616:29: note:   no known conversion for argument 1 from 'int' to 'std::__cxx11::basic_string<char>::const_iterator' {aka '__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >'}
 1616 |       insert(const_iterator __p, initializer_list<_CharT> __l)
      |              ~~~~~~~~~~~~~~~^~~
/usr/include/c++/9/bits/basic_string.h:1750:7: note: candidate: 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::iterator std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::insert(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::__const_iterator, _CharT) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::iterator = __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >; typename __gnu_cxx::__alloc_traits<typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_CharT>::other>::pointer = char*; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::__const_iterator = __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >; typename __gnu_cxx::__alloc_traits<typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_CharT>::other>::const_pointer = const char*]'
 1750 |       insert(__const_iterator __p, _CharT __c)
      |       ^~~~~~
/usr/include/c++/9/bits/basic_string.h:1750:31: note:   no known conversion for argument 1 from 'int' to 'std::__cxx11::basic_string<char>::__const_iterator' {aka '__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >'}
 1750 |       insert(__const_iterator __p, _CharT __c)
      |              ~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/9/bits/basic_string.h: In instantiation of 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const _CharT*, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]':
/usr/include/c++/9/system_error:354:51:   required from here
/usr/include/c++/9/bits/basic_string.h:6114:23: error: no matching function for call to 'std::__cxx11::basic_string<char>::insert(int, const char*&)'
 6114 |     { return std::move(__rhs.insert(0, __lhs)); }
      |              ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/basic_string.h:1582:9: note: candidate: 'template<class _InputIterator, class> std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::iterator std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::insert(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::const_iterator, _InputIterator, _InputIterator) [with _InputIterator = _InputIterator; <template-parameter-2-2> = <template-parameter-1-2>; _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]'
 1582 |         insert(const_iterator __p, _InputIterator __beg, _InputIterator __end)
      |         ^~~~~~
/usr/include/c++/9/bits/basic_string.h:1582:9: note:   template argument deduction/substitution failed:
/usr/include/c++/9/bits/basic_string.h:6114:23: note:   candidate expects 3 arguments, 2 provided
 6114 |     { return std::move(__rhs.insert(0, __lhs)); }
      |              ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/basic_string.h:1616:7: note: candidate: 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::iterator std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::insert(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::const_iterator, std::initializer_list<_Tp>) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::iterator = __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >; typename __gnu_cxx::__alloc_traits<typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_CharT>::other>::pointer = char*; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::const_iterator = __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >; typename __gnu_cxx::__alloc_traits<typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_CharT>::other>::const_pointer = const char*]'
 1616 |       insert(const_iterator __p, initializer_list<_CharT> __l)
      |       ^~~~~~
/usr/include/c++/9/bits/basic_string.h:1616:29: note:   no known conversion for argument 1 from 'int' to 'std::__cxx11::basic_string<char>::const_iterator' {aka '__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >'}
 1616 |       insert(const_iterator __p, initializer_list<_CharT> __l)
      |              ~~~~~~~~~~~~~~~^~~
/usr/include/c++/9/bits/basic_string.h:1750:7: note: candidate: 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::iterator std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::insert(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::__const_iterator, _CharT) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::iterator = __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >; typename __gnu_cxx::__alloc_traits<typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_CharT>::other>::pointer = char*; std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::__const_iterator = __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >; typename __gnu_cxx::__alloc_traits<typename __gnu_cxx::__alloc_traits<_Alloc>::rebind<_CharT>::other>::const_pointer = const char*]'
 1750 |       insert(__const_iterator __p, _CharT __c)
      |       ^~~~~~
/usr/include/c++/9/bits/basic_string.h:1750:31: note:   no known conversion for argument 1 from 'int' to 'std::__cxx11::basic_string<char>::__const_iterator' {aka '__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >'}
 1750 |       insert(__const_iterator __p, _CharT __c)
      |              ~~~~~~~~~~~~~~~~~^~~
In file included from /usr/include/c++/9/exception:143,
                 from /usr/include/c++/9/ios:39,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/exception_ptr.h: In instantiation of 'std::__exception_ptr::exception_ptr std::make_exception_ptr(_Ex) [with _Ex = std::future_error]':
/usr/include/c++/9/future:438:68:   required from here
/usr/include/c++/9/bits/exception_ptr.h:188:11: error: no matching function for call to 'operator new(sizetype, void*&)'
  188 |           ::new (__e) _Ex(__ex);
      |           ^~~~~~~~~~~~~~~~~~~~~
<built-in>: note: candidate: 'void* operator new(long unsigned int)'
<built-in>: note:   candidate expects 1 argument, 2 provided
In file included from /usr/include/c++/9/string:55,
                 from /usr/include/c++/9/bits/locale_classes.h:40,
                 from /usr/include/c++/9/bits/ios_base.h:41,
                 from /usr/include/c++/9/ios:42,
                 from /usr/include/c++/9/istream:38,
                 from /usr/include/c++/9/sstream:38,
                 from /usr/include/c++/9/complex:45,
                 from /usr/include/c++/9/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:54,
                 from foo.cc:2:
/usr/include/c++/9/bits/basic_string.h: In instantiation of 'void std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::_M_dispose() [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]':
/usr/include/c++/9/bits/basic_string.h:662:9:   required from 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::~basic_string() [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]'
/usr/include/c++/9/system_error:189:40:   required from here
/usr/include/c++/9/bits/basic_string.h:236:15: error: using invalid field 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::<unnamed union>::_M_allocated_capacity'
  236 |    _M_destroy(_M_allocated_capacity);
      |               ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/9/bits/locale_conv.h:41,
                 from /usr/include/c++/9/locale:43,
                 from /usr/include/c++/9/iomanip:43,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:72,
                 from foo.cc:2:
/usr/include/c++/9/bits/unique_ptr.h: In instantiation of 'std::__uniq_ptr_impl<_Tp, _Dp>::pointer& std::__uniq_ptr_impl<_Tp, _Dp>::_M_ptr() [with _Tp = std::__future_base::_Result_base; _Dp = std::__future_base::_Result_base::_Deleter; std::__uniq_ptr_impl<_Tp, _Dp>::pointer = std::__future_base::_Result_base*]':
/usr/include/c++/9/bits/unique_ptr.h:290:8:   required from 'std::unique_ptr<_Tp, _Dp>::~unique_ptr() [with _Tp = std::__future_base::_Result_base; _Dp = std::__future_base::_Result_base::_Deleter]'
/usr/include/c++/9/future:324:77:   required from here
/usr/include/c++/9/bits/unique_ptr.h:153:47: error: no matching function for call to 'get<0>(std::tuple<std::__future_base::_Result_base*, std::__future_base::_Result_base::_Deleter>&)'
  153 |       pointer&   _M_ptr() { return std::get<0>(_M_t); }
      |                                    ~~~~~~~~~~~^~~~~~
In file included from /usr/include/c++/9/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/utility:219:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int& std::get(std::pair<_Tp1, _Tp2>&)'
  219 |     get(std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:219:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:224:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int&& std::get(std::pair<_Tp1, _Tp2>&&)'
  224 |     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:224:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:229:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int& std::get(const std::pair<_Tp1, _Tp2>&)'
  229 |     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:229:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:234:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int&& std::get(const std::pair<_Tp1, _Tp2>&&)'
  234 |     get(const std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:234:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/array:307:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp& std::get(int&)'
  307 |     get(array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:307:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:316:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp&& std::get(int&&)'
  316 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:316:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:324:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp& std::get(const int&)'
  324 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:324:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:333:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp&& std::get(const int&&)'
  333 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:333:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/bits/locale_conv.h:41,
                 from /usr/include/c++/9/locale:43,
                 from /usr/include/c++/9/iomanip:43,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:72,
                 from foo.cc:2:
/usr/include/c++/9/bits/unique_ptr.h: In instantiation of 'std::__uniq_ptr_impl<_Tp, _Dp>::pointer& std::__uniq_ptr_impl<_Tp, _Dp>::_M_ptr() [with _Tp = std::__future_base::_State_baseV2::_Make_ready; _Dp = std::default_delete<std::__future_base::_State_baseV2::_Make_ready>; std::__uniq_ptr_impl<_Tp, _Dp>::pointer = std::__future_base::_State_baseV2::_Make_ready*]':
/usr/include/c++/9/bits/unique_ptr.h:290:8:   required from 'std::unique_ptr<_Tp, _Dp>::~unique_ptr() [with _Tp = std::__future_base::_State_baseV2::_Make_ready; _Dp = std::default_delete<std::__future_base::_State_baseV2::_Make_ready>]'
/usr/include/c++/9/future:419:46:   required from here
/usr/include/c++/9/bits/unique_ptr.h:153:47: error: no matching function for call to 'get<0>(std::tuple<std::__future_base::_State_baseV2::_Make_ready*, std::default_delete<std::__future_base::_State_baseV2::_Make_ready> >&)'
  153 |       pointer&   _M_ptr() { return std::get<0>(_M_t); }
      |                                    ~~~~~~~~~~~^~~~~~
In file included from /usr/include/c++/9/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/utility:219:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int& std::get(std::pair<_Tp1, _Tp2>&)'
  219 |     get(std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:219:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:224:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int&& std::get(std::pair<_Tp1, _Tp2>&&)'
  224 |     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:224:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:229:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int& std::get(const std::pair<_Tp1, _Tp2>&)'
  229 |     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:229:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:234:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int&& std::get(const std::pair<_Tp1, _Tp2>&&)'
  234 |     get(const std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:234:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/array:307:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp& std::get(int&)'
  307 |     get(array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:307:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:316:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp&& std::get(int&&)'
  316 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:316:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:324:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp& std::get(const int&)'
  324 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:324:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:333:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp&& std::get(const int&&)'
  333 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:333:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/bits/locale_conv.h:41,
                 from /usr/include/c++/9/locale:43,
                 from /usr/include/c++/9/iomanip:43,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:72,
                 from foo.cc:2:
/usr/include/c++/9/bits/unique_ptr.h: In instantiation of 'std::__uniq_ptr_impl<_Tp, _Dp>::pointer& std::__uniq_ptr_impl<_Tp, _Dp>::_M_ptr() [with _Tp = std::__future_base::_Result<void>; _Dp = std::__future_base::_Result_base::_Deleter; std::__uniq_ptr_impl<_Tp, _Dp>::pointer = std::__future_base::_Result<void>*]':
/usr/include/c++/9/bits/unique_ptr.h:290:8:   required from 'std::unique_ptr<_Tp, _Dp>::~unique_ptr() [with _Tp = std::__future_base::_Result<void>; _Dp = std::__future_base::_Result_base::_Deleter]'
/usr/include/c++/9/future:1258:28:   required from here
/usr/include/c++/9/bits/unique_ptr.h:153:47: error: no matching function for call to 'get<0>(std::tuple<std::__future_base::_Result<void>*, std::__future_base::_Result_base::_Deleter>&)'
  153 |       pointer&   _M_ptr() { return std::get<0>(_M_t); }
      |                                    ~~~~~~~~~~~^~~~~~
In file included from /usr/include/c++/9/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/utility:219:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int& std::get(std::pair<_Tp1, _Tp2>&)'
  219 |     get(std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:219:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:224:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int&& std::get(std::pair<_Tp1, _Tp2>&&)'
  224 |     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:224:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:229:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int& std::get(const std::pair<_Tp1, _Tp2>&)'
  229 |     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:229:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:234:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int&& std::get(const std::pair<_Tp1, _Tp2>&&)'
  234 |     get(const std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:234:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/array:307:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp& std::get(int&)'
  307 |     get(array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:307:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:316:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp&& std::get(int&&)'
  316 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:316:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:324:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp& std::get(const int&)'
  324 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:324:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:333:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp&& std::get(const int&&)'
  333 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:333:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/bits/locale_conv.h:41,
                 from /usr/include/c++/9/locale:43,
                 from /usr/include/c++/9/iomanip:43,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:72,
                 from foo.cc:2:
/usr/include/c++/9/bits/unique_ptr.h: In instantiation of '_Dp& std::__uniq_ptr_impl<_Tp, _Dp>::_M_deleter() [with _Tp = std::__future_base::_Result_base; _Dp = std::__future_base::_Result_base::_Deleter]':
/usr/include/c++/9/bits/unique_ptr.h:366:32:   required from 'std::unique_ptr<_Tp, _Dp>::deleter_type& std::unique_ptr<_Tp, _Dp>::get_deleter() [with _Tp = std::__future_base::_Result_base; _Dp = std::__future_base::_Result_base::_Deleter; std::unique_ptr<_Tp, _Dp>::deleter_type = std::__future_base::_Result_base::_Deleter]'
/usr/include/c++/9/bits/unique_ptr.h:292:17:   required from 'std::unique_ptr<_Tp, _Dp>::~unique_ptr() [with _Tp = std::__future_base::_Result_base; _Dp = std::__future_base::_Result_base::_Deleter]'
/usr/include/c++/9/future:324:77:   required from here
/usr/include/c++/9/bits/unique_ptr.h:155:51: error: no matching function for call to 'get<1>(std::tuple<std::__future_base::_Result_base*, std::__future_base::_Result_base::_Deleter>&)'
  155 |       _Dp&       _M_deleter() { return std::get<1>(_M_t); }
      |                                        ~~~~~~~~~~~^~~~~~
In file included from /usr/include/c++/9/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/utility:219:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int& std::get(std::pair<_Tp1, _Tp2>&)'
  219 |     get(std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:219:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:224:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int&& std::get(std::pair<_Tp1, _Tp2>&&)'
  224 |     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:224:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:229:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int& std::get(const std::pair<_Tp1, _Tp2>&)'
  229 |     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:229:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:234:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int&& std::get(const std::pair<_Tp1, _Tp2>&&)'
  234 |     get(const std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:234:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/array:307:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp& std::get(int&)'
  307 |     get(array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:307:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:316:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp&& std::get(int&&)'
  316 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:316:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:324:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp& std::get(const int&)'
  324 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:324:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:333:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp&& std::get(const int&&)'
  333 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:333:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/bits/locale_conv.h:41,
                 from /usr/include/c++/9/locale:43,
                 from /usr/include/c++/9/iomanip:43,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:72,
                 from foo.cc:2:
/usr/include/c++/9/bits/unique_ptr.h: In instantiation of 'std::__uniq_ptr_impl<_Tp, _Dp>::pointer std::__uniq_ptr_impl<_Tp, _Dp>::_M_ptr() const [with _Tp = std::__future_base::_Result_base; _Dp = std::__future_base::_Result_base::_Deleter; std::__uniq_ptr_impl<_Tp, _Dp>::pointer = std::__future_base::_Result_base*]':
/usr/include/c++/9/bits/unique_ptr.h:361:28:   required from 'std::unique_ptr<_Tp, _Dp>::pointer std::unique_ptr<_Tp, _Dp>::get() const [with _Tp = std::__future_base::_Result_base; _Dp = std::__future_base::_Result_base::_Deleter; std::unique_ptr<_Tp, _Dp>::pointer = std::__future_base::_Result_base*]'
/usr/include/c++/9/bits/unique_ptr.h:347:10:   required from 'typename std::add_lvalue_reference<_Tp>::type std::unique_ptr<_Tp, _Dp>::operator*() const [with _Tp = std::__future_base::_Result_base; _Dp = std::__future_base::_Result_base::_Deleter; typename std::add_lvalue_reference<_Tp>::type = std::__future_base::_Result_base&]'
/usr/include/c++/9/future:338:10:   required from here
/usr/include/c++/9/bits/unique_ptr.h:154:53: error: no matching function for call to 'get<0>(const std::tuple<std::__future_base::_Result_base*, std::__future_base::_Result_base::_Deleter>&)'
  154 |       pointer    _M_ptr() const { return std::get<0>(_M_t); }
      |                                          ~~~~~~~~~~~^~~~~~
In file included from /usr/include/c++/9/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/utility:219:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int& std::get(std::pair<_Tp1, _Tp2>&)'
  219 |     get(std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:219:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:224:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int&& std::get(std::pair<_Tp1, _Tp2>&&)'
  224 |     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:224:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:229:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int& std::get(const std::pair<_Tp1, _Tp2>&)'
  229 |     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:229:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:234:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int&& std::get(const std::pair<_Tp1, _Tp2>&&)'
  234 |     get(const std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:234:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/array:307:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp& std::get(int&)'
  307 |     get(array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:307:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:316:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp&& std::get(int&&)'
  316 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:316:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:324:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp& std::get(const int&)'
  324 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:324:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:333:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp&& std::get(const int&&)'
  333 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:333:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/bits/locale_conv.h:41,
                 from /usr/include/c++/9/locale:43,
                 from /usr/include/c++/9/iomanip:43,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:72,
                 from foo.cc:2:
/usr/include/c++/9/bits/unique_ptr.h: In instantiation of '_Dp& std::__uniq_ptr_impl<_Tp, _Dp>::_M_deleter() [with _Tp = std::__future_base::_State_baseV2::_Make_ready; _Dp = std::default_delete<std::__future_base::_State_baseV2::_Make_ready>]':
/usr/include/c++/9/bits/unique_ptr.h:366:32:   required from 'std::unique_ptr<_Tp, _Dp>::deleter_type& std::unique_ptr<_Tp, _Dp>::get_deleter() [with _Tp = std::__future_base::_State_baseV2::_Make_ready; _Dp = std::default_delete<std::__future_base::_State_baseV2::_Make_ready>; std::unique_ptr<_Tp, _Dp>::deleter_type = std::default_delete<std::__future_base::_State_baseV2::_Make_ready>]'
/usr/include/c++/9/bits/unique_ptr.h:292:17:   required from 'std::unique_ptr<_Tp, _Dp>::~unique_ptr() [with _Tp = std::__future_base::_State_baseV2::_Make_ready; _Dp = std::default_delete<std::__future_base::_State_baseV2::_Make_ready>]'
/usr/include/c++/9/future:419:46:   required from here
/usr/include/c++/9/bits/unique_ptr.h:155:51: error: no matching function for call to 'get<1>(std::tuple<std::__future_base::_State_baseV2::_Make_ready*, std::default_delete<std::__future_base::_State_baseV2::_Make_ready> >&)'
  155 |       _Dp&       _M_deleter() { return std::get<1>(_M_t); }
      |                                        ~~~~~~~~~~~^~~~~~
In file included from /usr/include/c++/9/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/utility:219:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int& std::get(std::pair<_Tp1, _Tp2>&)'
  219 |     get(std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:219:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:224:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int&& std::get(std::pair<_Tp1, _Tp2>&&)'
  224 |     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:224:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:229:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int& std::get(const std::pair<_Tp1, _Tp2>&)'
  229 |     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:229:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:234:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int&& std::get(const std::pair<_Tp1, _Tp2>&&)'
  234 |     get(const std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:234:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/array:307:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp& std::get(int&)'
  307 |     get(array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:307:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:316:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp&& std::get(int&&)'
  316 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:316:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:324:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp& std::get(const int&)'
  324 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:324:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:333:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp&& std::get(const int&&)'
  333 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:333:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/bits/locale_conv.h:41,
                 from /usr/include/c++/9/locale:43,
                 from /usr/include/c++/9/iomanip:43,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:72,
                 from foo.cc:2:
/usr/include/c++/9/bits/unique_ptr.h: In instantiation of 'std::__uniq_ptr_impl<_Tp, _Dp>::pointer std::__uniq_ptr_impl<_Tp, _Dp>::_M_ptr() const [with _Tp = std::__future_base::_State_baseV2::_Make_ready; _Dp = std::default_delete<std::__future_base::_State_baseV2::_Make_ready>; std::__uniq_ptr_impl<_Tp, _Dp>::pointer = std::__future_base::_State_baseV2::_Make_ready*]':
/usr/include/c++/9/bits/unique_ptr.h:361:28:   required from 'std::unique_ptr<_Tp, _Dp>::pointer std::unique_ptr<_Tp, _Dp>::get() const [with _Tp = std::__future_base::_State_baseV2::_Make_ready; _Dp = std::default_delete<std::__future_base::_State_baseV2::_Make_ready>; std::unique_ptr<_Tp, _Dp>::pointer = std::__future_base::_State_baseV2::_Make_ready*]'
/usr/include/c++/9/bits/unique_ptr.h:355:9:   required from 'std::unique_ptr<_Tp, _Dp>::pointer std::unique_ptr<_Tp, _Dp>::operator->() const [with _Tp = std::__future_base::_State_baseV2::_Make_ready; _Dp = std::default_delete<std::__future_base::_State_baseV2::_Make_ready>; std::unique_ptr<_Tp, _Dp>::pointer = std::__future_base::_State_baseV2::_Make_ready*]'
/usr/include/c++/9/future:426:6:   required from here
/usr/include/c++/9/bits/unique_ptr.h:154:53: error: no matching function for call to 'get<0>(const std::tuple<std::__future_base::_State_baseV2::_Make_ready*, std::default_delete<std::__future_base::_State_baseV2::_Make_ready> >&)'
  154 |       pointer    _M_ptr() const { return std::get<0>(_M_t); }
      |                                          ~~~~~~~~~~~^~~~~~
In file included from /usr/include/c++/9/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/utility:219:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int& std::get(std::pair<_Tp1, _Tp2>&)'
  219 |     get(std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:219:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:224:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int&& std::get(std::pair<_Tp1, _Tp2>&&)'
  224 |     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:224:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:229:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int& std::get(const std::pair<_Tp1, _Tp2>&)'
  229 |     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:229:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:234:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int&& std::get(const std::pair<_Tp1, _Tp2>&&)'
  234 |     get(const std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:234:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/array:307:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp& std::get(int&)'
  307 |     get(array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:307:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:316:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp&& std::get(int&&)'
  316 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:316:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:324:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp& std::get(const int&)'
  324 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:324:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:333:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp&& std::get(const int&&)'
  333 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:333:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/bits/locale_conv.h:41,
                 from /usr/include/c++/9/locale:43,
                 from /usr/include/c++/9/iomanip:43,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:72,
                 from foo.cc:2:
/usr/include/c++/9/bits/unique_ptr.h: In instantiation of '_Dp& std::__uniq_ptr_impl<_Tp, _Dp>::_M_deleter() [with _Tp = std::__future_base::_Result<void>; _Dp = std::__future_base::_Result_base::_Deleter]':
/usr/include/c++/9/bits/unique_ptr.h:366:32:   required from 'std::unique_ptr<_Tp, _Dp>::deleter_type& std::unique_ptr<_Tp, _Dp>::get_deleter() [with _Tp = std::__future_base::_Result<void>; _Dp = std::__future_base::_Result_base::_Deleter; std::unique_ptr<_Tp, _Dp>::deleter_type = std::__future_base::_Result_base::_Deleter]'
/usr/include/c++/9/bits/unique_ptr.h:292:17:   required from 'std::unique_ptr<_Tp, _Dp>::~unique_ptr() [with _Tp = std::__future_base::_Result<void>; _Dp = std::__future_base::_Result_base::_Deleter]'
/usr/include/c++/9/future:1258:28:   required from here
/usr/include/c++/9/bits/unique_ptr.h:155:51: error: no matching function for call to 'get<1>(std::tuple<std::__future_base::_Result<void>*, std::__future_base::_Result_base::_Deleter>&)'
  155 |       _Dp&       _M_deleter() { return std::get<1>(_M_t); }
      |                                        ~~~~~~~~~~~^~~~~~
In file included from /usr/include/c++/9/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/utility:219:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int& std::get(std::pair<_Tp1, _Tp2>&)'
  219 |     get(std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:219:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:224:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int&& std::get(std::pair<_Tp1, _Tp2>&&)'
  224 |     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:224:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:229:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int& std::get(const std::pair<_Tp1, _Tp2>&)'
  229 |     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:229:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:234:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int&& std::get(const std::pair<_Tp1, _Tp2>&&)'
  234 |     get(const std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:234:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/array:307:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp& std::get(int&)'
  307 |     get(array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:307:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:316:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp&& std::get(int&&)'
  316 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:316:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:324:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp& std::get(const int&)'
  324 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:324:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:333:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp&& std::get(const int&&)'
  333 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:333:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/functional:59,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/bits/std_function.h: In instantiation of 'static void std::_Function_base::_Base_manager<_Functor>::_M_init_functor(std::_Any_data&, _Functor&&, std::true_type) [with _Functor = std::__future_base::_State_baseV2::_Setter<void, void>; std::true_type = std::integral_constant<bool, true>]':
/usr/include/c++/9/bits/std_function.h:223:19:   required from 'static void std::_Function_base::_Base_manager<_Functor>::_M_init_functor(std::_Any_data&, _Functor&&) [with _Functor = std::__future_base::_State_baseV2::_Setter<void, void>]'
/usr/include/c++/9/bits/std_function.h:675:34:   required from 'std::function<_Res(_ArgTypes ...)>::function(_Functor) [with _Functor = std::__future_base::_State_baseV2::_Setter<void, void>; <template-parameter-2-2> = void; <template-parameter-2-3> = void; _Res = std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter>; _ArgTypes = {}]'
/usr/include/c++/9/future:1313:56:   required from here
/usr/include/c++/9/bits/std_function.h:248:4: error: no matching function for call to 'operator new(sizetype, void*)'
  248 |  { ::new (__functor._M_access()) _Functor(std::move(__f)); }
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<built-in>: note: candidate: 'void* operator new(long unsigned int)'
<built-in>: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/9/bits/std_function.h: In instantiation of 'static void std::_Function_base::_Base_manager<_Functor>::_M_clone(std::_Any_data&, const std::_Any_data&, std::true_type) [with _Functor = std::__future_base::_State_baseV2::_Setter<void, void>; std::true_type = std::integral_constant<bool, true>]':
/usr/include/c++/9/bits/std_function.h:211:16:   required from 'static bool std::_Function_base::_Base_manager<_Functor>::_M_manager(std::_Any_data&, const std::_Any_data&, std::_Manager_operation) [with _Functor = std::__future_base::_State_baseV2::_Setter<void, void>]'
/usr/include/c++/9/bits/std_function.h:677:19:   required from 'std::function<_Res(_ArgTypes ...)>::function(_Functor) [with _Functor = std::__future_base::_State_baseV2::_Setter<void, void>; <template-parameter-2-2> = void; <template-parameter-2-3> = void; _Res = std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter>; _ArgTypes = {}]'
/usr/include/c++/9/future:1313:56:   required from here
/usr/include/c++/9/bits/std_function.h:167:4: error: no matching function for call to 'operator new(sizetype, void*)'
  167 |    ::new (__dest._M_access()) _Functor(__source._M_access<_Functor>());
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<built-in>: note: candidate: 'void* operator new(long unsigned int)'
<built-in>: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/9/bits/std_function.h: In instantiation of 'static void std::_Function_base::_Base_manager<_Functor>::_M_init_functor(std::_Any_data&, _Functor&&, std::true_type) [with _Functor = std::__future_base::_State_baseV2::_Setter<void, std::__future_base::_State_baseV2::__exception_ptr_tag>; std::true_type = std::integral_constant<bool, true>]':
/usr/include/c++/9/bits/std_function.h:223:19:   required from 'static void std::_Function_base::_Base_manager<_Functor>::_M_init_functor(std::_Any_data&, _Functor&&) [with _Functor = std::__future_base::_State_baseV2::_Setter<void, std::__future_base::_State_baseV2::__exception_ptr_tag>]'
/usr/include/c++/9/bits/std_function.h:675:34:   required from 'std::function<_Res(_ArgTypes ...)>::function(_Functor) [with _Functor = std::__future_base::_State_baseV2::_Setter<void, std::__future_base::_State_baseV2::__exception_ptr_tag>; <template-parameter-2-2> = void; <template-parameter-2-3> = void; _Res = std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter>; _ArgTypes = {}]'
/usr/include/c++/9/future:1317:61:   required from here
/usr/include/c++/9/bits/std_function.h:248:4: error: no matching function for call to 'operator new(sizetype, void*)'
  248 |  { ::new (__functor._M_access()) _Functor(std::move(__f)); }
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<built-in>: note: candidate: 'void* operator new(long unsigned int)'
<built-in>: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/9/bits/std_function.h: In instantiation of 'static void std::_Function_base::_Base_manager<_Functor>::_M_clone(std::_Any_data&, const std::_Any_data&, std::true_type) [with _Functor = std::__future_base::_State_baseV2::_Setter<void, std::__future_base::_State_baseV2::__exception_ptr_tag>; std::true_type = std::integral_constant<bool, true>]':
/usr/include/c++/9/bits/std_function.h:211:16:   required from 'static bool std::_Function_base::_Base_manager<_Functor>::_M_manager(std::_Any_data&, const std::_Any_data&, std::_Manager_operation) [with _Functor = std::__future_base::_State_baseV2::_Setter<void, std::__future_base::_State_baseV2::__exception_ptr_tag>]'
/usr/include/c++/9/bits/std_function.h:677:19:   required from 'std::function<_Res(_ArgTypes ...)>::function(_Functor) [with _Functor = std::__future_base::_State_baseV2::_Setter<void, std::__future_base::_State_baseV2::__exception_ptr_tag>; <template-parameter-2-2> = void; <template-parameter-2-3> = void; _Res = std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter>; _ArgTypes = {}]'
/usr/include/c++/9/future:1317:61:   required from here
/usr/include/c++/9/bits/std_function.h:167:4: error: no matching function for call to 'operator new(sizetype, void*)'
  167 |    ::new (__dest._M_access()) _Functor(__source._M_access<_Functor>());
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<built-in>: note: candidate: 'void* operator new(long unsigned int)'
<built-in>: note:   candidate expects 1 argument, 2 provided
In file included from /usr/include/c++/9/bits/locale_conv.h:41,
                 from /usr/include/c++/9/locale:43,
                 from /usr/include/c++/9/iomanip:43,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:72,
                 from foo.cc:2:
/usr/include/c++/9/bits/unique_ptr.h: In instantiation of 'std::__uniq_ptr_impl<_Tp, _Dp>::pointer std::__uniq_ptr_impl<_Tp, _Dp>::_M_ptr() const [with _Tp = std::__future_base::_Result<void>; _Dp = std::__future_base::_Result_base::_Deleter; std::__uniq_ptr_impl<_Tp, _Dp>::pointer = std::__future_base::_Result<void>*]':
/usr/include/c++/9/bits/unique_ptr.h:361:28:   required from 'std::unique_ptr<_Tp, _Dp>::pointer std::unique_ptr<_Tp, _Dp>::get() const [with _Tp = std::__future_base::_Result<void>; _Dp = std::__future_base::_Result_base::_Deleter; std::unique_ptr<_Tp, _Dp>::pointer = std::__future_base::_Result<void>*]'
/usr/include/c++/9/bits/unique_ptr.h:383:16:   required from 'std::unique_ptr<_Tp, _Dp>::pointer std::unique_ptr<_Tp, _Dp>::release() [with _Tp = std::__future_base::_Result<void>; _Dp = std::__future_base::_Result_base::_Deleter; std::unique_ptr<_Tp, _Dp>::pointer = std::__future_base::_Result<void>*]'
/usr/include/c++/9/bits/unique_ptr.h:258:18:   required from 'std::unique_ptr<_Tp, _Dp>::unique_ptr(std::unique_ptr<_Tp, _Dp>&&) [with _Tp = std::__future_base::_Result<void>; _Dp = std::__future_base::_Result_base::_Deleter]'
/usr/include/c++/9/future:1263:40:   required from here
/usr/include/c++/9/bits/unique_ptr.h:154:53: error: no matching function for call to 'get<0>(const std::tuple<std::__future_base::_Result<void>*, std::__future_base::_Result_base::_Deleter>&)'
  154 |       pointer    _M_ptr() const { return std::get<0>(_M_t); }
      |                                          ~~~~~~~~~~~^~~~~~
In file included from /usr/include/c++/9/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:65,
                 from foo.cc:2:
/usr/include/c++/9/utility:219:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int& std::get(std::pair<_Tp1, _Tp2>&)'
  219 |     get(std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:219:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:224:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr int&& std::get(std::pair<_Tp1, _Tp2>&&)'
  224 |     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:224:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:229:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int& std::get(const std::pair<_Tp1, _Tp2>&)'
  229 |     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:229:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/utility:234:5: note: candidate: 'template<<declaration error>, class _Tp1, class _Tp2> constexpr const int&& std::get(const std::pair<_Tp1, _Tp2>&&)'
  234 |     get(const std::pair<_Tp1, _Tp2>&& __in) noexcept
      |     ^~~
/usr/include/c++/9/utility:234:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/tuple:39,
                 from /usr/include/c++/9/functional:54,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:71,
                 from foo.cc:2:
/usr/include/c++/9/array:307:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp& std::get(int&)'
  307 |     get(array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:307:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:316:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr _Tp&& std::get(int&&)'
  316 |     get(array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:316:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:324:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp& std::get(const int&)'
  324 |     get(const array<_Tp, _Nm>& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:324:5: note:   template argument deduction/substitution failed:
/usr/include/c++/9/array:333:5: note: candidate: 'template<<declaration error>, class _Tp, <declaration error> > constexpr const _Tp&& std::get(const int&&)'
  333 |     get(const array<_Tp, _Nm>&& __arr) noexcept
      |     ^~~
/usr/include/c++/9/array:333:5: note:   template argument deduction/substitution failed:
In file included from /usr/include/c++/9/bits/shared_ptr.h:52,
                 from /usr/include/c++/9/memory:81,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:82,
                 from foo.cc:2:
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of 'std::__shared_count<_Lp>::__shared_count(_Tp*&, std::_Sp_alloc_shared_tag<_Alloc>, _Args&& ...) [with _Tp = std::mutex; _Alloc = std::allocator<std::mutex>; _Args = {}; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]':
/usr/include/c++/9/bits/shared_ptr_base.h:1344:71:   required from 'std::__shared_ptr<_Tp, _Lp>::__shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<std::mutex>; _Args = {}; _Tp = std::mutex; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]'
/usr/include/c++/9/bits/shared_ptr.h:359:59:   required from 'std::shared_ptr<_Tp>::shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<std::mutex>; _Args = {}; _Tp = std::mutex]'
/usr/include/c++/9/bits/shared_ptr.h:701:14:   required from 'std::shared_ptr<_Tp> std::allocate_shared(const _Alloc&, _Args&& ...) [with _Tp = std::mutex; _Alloc = std::allocator<std::mutex>; _Args = {}]'
/usr/include/c++/9/bits/shared_ptr.h:717:39:   required from 'std::shared_ptr<_Tp> std::make_shared(_Args&& ...) [with _Tp = std::mutex; _Args = {}]'
/usr/include/c++/9/condition_variable:243:65:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:679:16: error: no matching function for call to 'operator new(sizetype, _Sp_cp_type*&)'
  679 |    auto __pi = ::new (__mem)
      |                ^~~~~~~~~~~~~
  680 |      _Sp_cp_type(__a._M_a, std::forward<_Args>(__args)...);
      |      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<built-in>: note: candidate: 'void* operator new(long unsigned int)'
<built-in>: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/9/bits/shared_ptr_base.h:681:12: error: no match for 'operator=' (operand types are 'std::__allocated_ptr<std::allocator<std::_Sp_counted_ptr_inplace<std::mutex, std::allocator<std::mutex>, __gnu_cxx::_S_atomic> > >' and 'std::nullptr_t')
  681 |    __guard = nullptr;
      |    ~~~~~~~~^~~~~~~~~
In file included from /usr/include/c++/9/bits/stl_list.h:63,
                 from /usr/include/c++/9/list:63,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:79,
                 from foo.cc:2:
/usr/include/c++/9/bits/allocated_ptr.h:46:12: note: candidate: 'std::__allocated_ptr<std::allocator<std::_Sp_counted_ptr_inplace<std::mutex, std::allocator<std::mutex>, __gnu_cxx::_S_atomic> > >& std::__allocated_ptr<std::allocator<std::_Sp_counted_ptr_inplace<std::mutex, std::allocator<std::mutex>, __gnu_cxx::_S_atomic> > >::operator=(const std::__allocated_ptr<std::allocator<std::_Sp_counted_ptr_inplace<std::mutex, std::allocator<std::mutex>, __gnu_cxx::_S_atomic> > >&)' <deleted>
   46 |     struct __allocated_ptr
      |            ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/allocated_ptr.h:46:12: note:   no known conversion for argument 1 from 'std::nullptr_t' to 'const std::__allocated_ptr<std::allocator<std::_Sp_counted_ptr_inplace<std::mutex, std::allocator<std::mutex>, __gnu_cxx::_S_atomic> > >&'
In file included from /usr/include/c++/9/bits/shared_ptr.h:52,
                 from /usr/include/c++/9/memory:81,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:82,
                 from foo.cc:2:
/usr/include/c++/9/bits/shared_ptr_base.h: In instantiation of 'std::__shared_count<_Lp>::__shared_count(_Tp*&, std::_Sp_alloc_shared_tag<_Alloc>, _Args&& ...) [with _Tp = std::__future_base::_State_baseV2; _Alloc = std::allocator<std::__future_base::_State_baseV2>; _Args = {}; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]':
/usr/include/c++/9/bits/shared_ptr_base.h:1344:71:   required from 'std::__shared_ptr<_Tp, _Lp>::__shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<std::__future_base::_State_baseV2>; _Args = {}; _Tp = std::__future_base::_State_baseV2; __gnu_cxx::_Lock_policy _Lp = __gnu_cxx::_S_atomic]'
/usr/include/c++/9/bits/shared_ptr.h:359:59:   required from 'std::shared_ptr<_Tp>::shared_ptr(std::_Sp_alloc_shared_tag<_Tp>, _Args&& ...) [with _Alloc = std::allocator<std::__future_base::_State_baseV2>; _Args = {}; _Tp = std::__future_base::_State_baseV2]'
/usr/include/c++/9/bits/shared_ptr.h:701:14:   required from 'std::shared_ptr<_Tp> std::allocate_shared(const _Alloc&, _Args&& ...) [with _Tp = std::__future_base::_State_baseV2; _Alloc = std::allocator<std::__future_base::_State_baseV2>; _Args = {}]'
/usr/include/c++/9/bits/shared_ptr.h:717:39:   required from 'std::shared_ptr<_Tp> std::make_shared(_Args&& ...) [with _Tp = std::__future_base::_State_baseV2; _Args = {}]'
/usr/include/c++/9/future:1257:44:   required from here
/usr/include/c++/9/bits/shared_ptr_base.h:679:16: error: no matching function for call to 'operator new(sizetype, _Sp_cp_type*&)'
  679 |    auto __pi = ::new (__mem)
      |                ^~~~~~~~~~~~~
  680 |      _Sp_cp_type(__a._M_a, std::forward<_Args>(__args)...);
      |      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<built-in>: note: candidate: 'void* operator new(long unsigned int)'
<built-in>: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/9/bits/shared_ptr_base.h:681:12: error: no match for 'operator=' (operand types are 'std::__allocated_ptr<std::allocator<std::_Sp_counted_ptr_inplace<std::__future_base::_State_baseV2, std::allocator<std::__future_base::_State_baseV2>, __gnu_cxx::_S_atomic> > >' and 'std::nullptr_t')
  681 |    __guard = nullptr;
      |    ~~~~~~~~^~~~~~~~~
In file included from /usr/include/c++/9/bits/stl_list.h:63,
                 from /usr/include/c++/9/list:63,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:79,
                 from foo.cc:2:
/usr/include/c++/9/bits/allocated_ptr.h:46:12: note: candidate: 'std::__allocated_ptr<std::allocator<std::_Sp_counted_ptr_inplace<std::__future_base::_State_baseV2, std::allocator<std::__future_base::_State_baseV2>, __gnu_cxx::_S_atomic> > >& std::__allocated_ptr<std::allocator<std::_Sp_counted_ptr_inplace<std::__future_base::_State_baseV2, std::allocator<std::__future_base::_State_baseV2>, __gnu_cxx::_S_atomic> > >::operator=(const std::__allocated_ptr<std::allocator<std::_Sp_counted_ptr_inplace<std::__future_base::_State_baseV2, std::allocator<std::__future_base::_State_baseV2>, __gnu_cxx::_S_atomic> > >&)' <deleted>
   46 |     struct __allocated_ptr
      |            ^~~~~~~~~~~~~~~
/usr/include/c++/9/bits/allocated_ptr.h:46:12: note:   no known conversion for argument 1 from 'std::nullptr_t' to 'const std::__allocated_ptr<std::allocator<std::_Sp_counted_ptr_inplace<std::__future_base::_State_baseV2, std::allocator<std::__future_base::_State_baseV2>, __gnu_cxx::_S_atomic> > >&'

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