Compile Error

foo.cc: In function 'int main()':
foo.cc:14:15: warning: left shift count >= width of type [-Wshift-count-overflow]
   14 |    cout<a[i]<<' ';
      |               ^~~
foo.cc:14:8: error: no match for 'operator<' (operand types are 'std::ostream' {aka 'std::basic_ostream<char>'} and 'int')
   14 |    cout<a[i]<<' ';
      |    ~~~~^~~~~~~~~~
      |    |        |
      |    |        int
      |    std::ostream {aka std::basic_ostream<char>}
foo.cc:14:8: note: candidate: 'operator<(int, int)' <built-in>
   14 |    cout<a[i]<<' ';
      |    ~~~~^~~~~~~~~~
foo.cc:14:8: note:   no known conversion for argument 1 from 'std::ostream' {aka 'std::basic_ostream<char>'} to 'int'
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:1:
/usr/include/c++/9/bits/regex.h:1048:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator<(const std::__cxx11::sub_match<_BiIter>&, const std::__cxx11::sub_match<_BiIter>&)'
 1048 |     operator<(const sub_match<_BiIter>& __lhs, const sub_match<_BiIter>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/9/bits/regex.h:1048:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/regex.h:1124:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator<(std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&, const std::__cxx11::sub_match<_BiIter>&)'
 1124 |     operator<(const __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/regex.h:1124:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/regex.h:1198:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator<(const std::__cxx11::sub_match<_BiIter>&, std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&)'
 1198 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/regex.h:1198:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/regex.h:1272:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const typename std::iterator_traits<_Iter>::value_type*, const std::__cxx11::sub_match<_BiIter>&)'
 1272 |     operator<(typename iterator_traits<_Bi_iter>::value_type const* __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/regex.h:1272:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'int'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/regex.h:1346:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const std::__cxx11::sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type*)'
 1346 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/regex.h:1346:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/regex.h:1421:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const typename std::iterator_traits<_Iter>::value_type&, const std::__cxx11::sub_match<_BiIter>&)'
 1421 |     operator<(typename iterator_traits<_Bi_iter>::value_type const& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/regex.h:1421:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'int'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/regex.h:1499:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const std::__cxx11::sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type&)'
 1499 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/regex.h:1499:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/stl_pair.h:454:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator<(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)'
  454 |     operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_pair.h:454:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::pair<_T1, _T2>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/bits/stl_algobase.h:67,
                 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:1:
/usr/include/c++/9/bits/stl_iterator.h:331:5: note: candidate: 'template<class _Iterator> bool std::operator<(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)'
  331 |     operator<(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:331:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::reverse_iterator<_Iterator>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/bits/stl_algobase.h:67,
                 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:1:
/usr/include/c++/9/bits/stl_iterator.h:369:5: note: candidate: 'template<class _IteratorL, class _IteratorR> bool std::operator<(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)'
  369 |     operator<(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:369:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::reverse_iterator<_Iterator>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/bits/stl_algobase.h:67,
                 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:1:
/usr/include/c++/9/bits/stl_iterator.h:1160:5: note: candidate: 'template<class _IteratorL, class _IteratorR> bool std::operator<(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)'
 1160 |     operator<(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:1160:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::move_iterator<_IteratorL>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/bits/stl_algobase.h:67,
                 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:1:
/usr/include/c++/9/bits/stl_iterator.h:1166:5: note: candidate: 'template<class _Iterator> bool std::operator<(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)'
 1166 |     operator<(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:1166:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::move_iterator<_IteratorL>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/basic_string.h:6229:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
 6229 |     operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6229:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/basic_string.h:6242:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)'
 6242 |     operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6242:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/basic_string.h:6254:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
 6254 |     operator<(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6254:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/bits/ios_base.h:46,
                 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:1:
/usr/include/c++/9/system_error:208:3: note: candidate: 'bool std::operator<(const std::error_code&, const std::error_code&)'
  208 |   operator<(const error_code& __lhs, const error_code& __rhs) noexcept
      |   ^~~~~~~~
/usr/include/c++/9/system_error:208:31: note:   no known conversion for argument 1 from 'std::ostream' {aka 'std::basic_ostream<char>'} to 'const std::error_code&'
  208 |   operator<(const error_code& __lhs, const error_code& __rhs) noexcept
      |             ~~~~~~~~~~~~~~~~~~^~~~~
/usr/include/c++/9/system_error:282:3: note: candidate: 'bool std::operator<(const std::error_condition&, const std::error_condition&)'
  282 |   operator<(const error_condition& __lhs,
      |   ^~~~~~~~
/usr/include/c++/9/system_error:282:36: note:   no known conversion for argument 1 from 'std::ostream' {aka 'std::basic_ostream<char>'} to 'const std::error_condition&'
  282 |   operator<(const error_condition& __lhs,
      |             ~~~~~~~~~~~~~~~~~~~~~~~^~~~~
In file included from /usr/include/c++/9/deque:67,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:68,
                 from foo.cc:1:
/usr/include/c++/9/bits/stl_deque.h:312:5: note: candidate: 'template<class _Tp, class _Ref, class _Ptr> bool std::operator<(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _Ref, _Ptr>&)'
  312 |     operator<(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_deque.h:312:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/deque:67,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:68,
                 from foo.cc:1:
/usr/include/c++/9/bits/stl_deque.h:320:5: note: candidate: 'template<class _Tp, class _RefL, class _PtrL, class _RefR, class _PtrR> bool std::operator<(const std::_Deque_iterator<_Tp, _Ref, _Ptr>&, const std::_Deque_iterator<_Tp, _RefR, _PtrR>&)'
  320 |     operator<(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_deque.h:320:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::_Deque_iterator<_Tp, _Ref, _Ptr>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/deque:67,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:68,
                 from foo.cc:1:
/usr/include/c++/9/bits/stl_deque.h:2330:5: note: candidate: 'template<class _Tp, class _Alloc> bool std::operator<(const std::deque<_Tp, _Alloc>&, const std::deque<_Tp, _Alloc>&)'
 2330 |     operator<(const deque<_Tp, _Alloc>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_deque.h:2330:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::deque<_Tp, _Alloc>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/array:262:5: note: candidate: 'template<class _Tp, long unsigned int _Nm> bool std::operator<(const std::array<_Tp, _Nm>&, const std::array<_Tp, _Nm>&)'
  262 |     operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
      |     ^~~~~~~~
/usr/include/c++/9/array:262:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::array<_Tp, _Nm>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/tuple:1432:5: note: candidate: 'template<class ... _TElements, class ... _UElements> constexpr bool std::operator<(const std::tuple<_Tps ...>&, const std::tuple<_Elements ...>&)'
 1432 |     operator<(const tuple<_TElements...>& __t,
      |     ^~~~~~~~
/usr/include/c++/9/tuple:1432:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::tuple<_Tps ...>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/unique_ptr.h:749:5: note: candidate: 'template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator<(const std::unique_ptr<_Tp, _Dp>&, const std::unique_ptr<_Up, _Ep>&)'
  749 |     operator<(const unique_ptr<_Tp, _Dp>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/unique_ptr.h:749:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::unique_ptr<_Tp, _Dp>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/unique_ptr.h:760:5: note: candidate: 'template<class _Tp, class _Dp> bool std::operator<(const std::unique_ptr<_Tp, _Dp>&, std::nullptr_t)'
  760 |     operator<(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
      |     ^~~~~~~~
/usr/include/c++/9/bits/unique_ptr.h:760:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::unique_ptr<_Tp, _Dp>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/unique_ptr.h:766:5: note: candidate: 'template<class _Tp, class _Dp> bool std::operator<(std::nullptr_t, const std::unique_ptr<_Tp, _Dp>&)'
  766 |     operator<(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
      |     ^~~~~~~~
/usr/include/c++/9/bits/unique_ptr.h:766:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   mismatched types 'const std::unique_ptr<_Tp, _Dp>' and 'int'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/stl_list.h:2025:5: note: candidate: 'template<class _Tp, class _Alloc> bool std::operator<(const std::__cxx11::list<_Tp, _Alloc>&, const std::__cxx11::list<_Tp, _Alloc>&)'
 2025 |     operator<(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_list.h:2025:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/map:61,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:81,
                 from foo.cc:1:
/usr/include/c++/9/bits/stl_map.h:1472:5: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator<(const std::map<_Key, _Tp, _Compare, _Alloc>&, const std::map<_Key, _Tp, _Compare, _Alloc>&)'
 1472 |     operator<(const map<_Key, _Tp, _Compare, _Alloc>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_map.h:1472:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/map:62,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:81,
                 from foo.cc:1:
/usr/include/c++/9/bits/stl_multimap.h:1136:5: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator<(const std::multimap<_Key, _Tp, _Compare, _Alloc>&, const std::multimap<_Key, _Tp, _Compare, _Alloc>&)'
 1136 |     operator<(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_multimap.h:1136:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/shared_ptr_base.h:1444:5: note: candidate: 'template<class _Tp, class _Up, __gnu_cxx::_Lock_policy _Lp> bool std::operator<(const std::__shared_ptr<_Tp1, _Lp>&, const std::__shared_ptr<_Tp2, _Lp>&)'
 1444 |     operator<(const __shared_ptr<_Tp, _Lp>& __a,
      |     ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1444:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::__shared_ptr<_Tp1, _Lp>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/shared_ptr_base.h:1455:5: note: candidate: 'template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator<(const std::__shared_ptr<_Tp, _Lp>&, std::nullptr_t)'
 1455 |     operator<(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
      |     ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1455:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/shared_ptr_base.h:1463:5: note: candidate: 'template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator<(std::nullptr_t, const std::__shared_ptr<_Tp, _Lp>&)'
 1463 |     operator<(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
      |     ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr_base.h:1463:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   mismatched types 'const std::__shared_ptr<_Tp, _Lp>' and 'int'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/memory:81,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:82,
                 from foo.cc:1:
/usr/include/c++/9/bits/shared_ptr.h:413:5: note: candidate: 'template<class _Tp, class _Up> bool std::operator<(const std::shared_ptr<_Tp>&, const std::shared_ptr<_Tp>&)'
  413 |     operator<(const shared_ptr<_Tp>& __a, const shared_ptr<_Up>& __b) noexcept
      |     ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:413:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::shared_ptr<_Tp>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/memory:81,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:82,
                 from foo.cc:1:
/usr/include/c++/9/bits/shared_ptr.h:423:5: note: candidate: 'template<class _Tp> bool std::operator<(const std::shared_ptr<_Tp>&, std::nullptr_t)'
  423 |     operator<(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
      |     ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:423:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::shared_ptr<_Tp>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/memory:81,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:82,
                 from foo.cc:1:
/usr/include/c++/9/bits/shared_ptr.h:431:5: note: candidate: 'template<class _Tp> bool std::operator<(std::nullptr_t, const std::shared_ptr<_Tp>&)'
  431 |     operator<(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
      |     ^~~~~~~~
/usr/include/c++/9/bits/shared_ptr.h:431:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   mismatched types 'const std::shared_ptr<_Tp>' and 'int'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/vector:67,
                 from /usr/include/c++/9/queue:61,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:86,
                 from foo.cc:1:
/usr/include/c++/9/bits/stl_vector.h:1905:5: note: candidate: 'template<class _Tp, class _Alloc> bool std::operator<(const std::vector<_Tp, _Alloc>&, const std::vector<_Tp, _Alloc>&)'
 1905 |     operator<(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_vector.h:1905:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::vector<_Tp, _Alloc>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/queue:64,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:86,
                 from foo.cc:1:
/usr/include/c++/9/bits/stl_queue.h:356:5: note: candidate: 'template<class _Tp, class _Seq> bool std::operator<(const std::queue<_Tp, _Seq>&, const std::queue<_Tp, _Seq>&)'
  356 |     operator<(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y)
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_queue.h:356:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::queue<_Tp, _Seq>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/set:61,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:87,
                 from foo.cc:1:
/usr/include/c++/9/bits/stl_set.h:996:5: note: candidate: 'template<class _Key, class _Compare, class _Alloc> bool std::operator<(const std::set<_Key, _Compare, _Alloc>&, const std::set<_Key, _Compare, _Alloc>&)'
  996 |     operator<(const set<_Key, _Compare, _Alloc>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_set.h:996:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::set<_Key, _Compare, _Alloc>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/set:62,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:87,
                 from foo.cc:1:
/usr/include/c++/9/bits/stl_multiset.h:981:5: note: candidate: 'template<class _Key, class _Compare, class _Alloc> bool std::operator<(const std::multiset<_Key, _Compare, _Alloc>&, const std::multiset<_Key, _Compare, _Alloc>&)'
  981 |     operator<(const multiset<_Key, _Compare, _Alloc>& __x,
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_multiset.h:981:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::multiset<_Key, _Compare, _Alloc>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/stack:61,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:89,
                 from foo.cc:1:
/usr/include/c++/9/bits/stl_stack.h:331:5: note: candidate: 'template<class _Tp, class _Seq> bool std::operator<(const std::stack<_Tp, _Seq>&, const std::stack<_Tp, _Seq>&)'
  331 |     operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
      |     ^~~~~~~~
/usr/include/c++/9/bits/stl_stack.h:331:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::stack<_Tp, _Seq>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/valarray:603,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:95,
                 from foo.cc:1:
/usr/include/c++/9/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__less, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const std::_Expr<_Dom1, typename _Dom1::value_type>&, const std::_Expr<_Dom2, typename _Dom2::value_type>&)'
  419 |     _DEFINE_EXPR_BINARY_OPERATOR(<, __less)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/valarray_after.h:419:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/valarray:603,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:95,
                 from foo.cc:1:
/usr/include/c++/9/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__less, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const std::_Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  419 |     _DEFINE_EXPR_BINARY_OPERATOR(<, __less)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/valarray_after.h:419:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/valarray:603,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:95,
                 from foo.cc:1:
/usr/include/c++/9/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__less, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const typename _Dom::value_type&, const std::_Expr<_Dom1, typename _Dom1::value_type>&)'
  419 |     _DEFINE_EXPR_BINARY_OPERATOR(<, __less)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/valarray_after.h:419:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/valarray:603,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:95,
                 from foo.cc:1:
/usr/include/c++/9/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__less, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const std::_Expr<_Dom1, typename _Dom1::value_type>&, const std::valarray<typename _Dom::value_type>&)'
  419 |     _DEFINE_EXPR_BINARY_OPERATOR(<, __less)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/valarray_after.h:419:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/c++/9/valarray:603,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:95,
                 from foo.cc:1:
/usr/include/c++/9/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__less, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const std::valarray<typename _Dom::value_type>&, const std::_Expr<_Dom1, typename _Dom1::value_type>&)'
  419 |     _DEFINE_EXPR_BINARY_OPERATOR(<, __less)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/valarray_after.h:419:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:95,
                 from foo.cc:1:
/usr/include/c++/9/valarray:1199:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__less, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__less, _Tp>::result_type> std::operator<(const std::valarray<_Tp>&, const std::valarray<_Tp>&)'
 1199 | _DEFINE_BINARY_OPERATOR(<, __less)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/valarray:1199:1: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::valarray<_Tp>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:95,
                 from foo.cc:1:
/usr/include/c++/9/valarray:1199:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__less, std::_ValArray, std::_Constant, _Tp, _Tp>, typename std::__fun<std::__less, _Tp>::result_type> std::operator<(const std::valarray<_Tp>&, const typename std::valarray<_Tp>::value_type&)'
 1199 | _DEFINE_BINARY_OPERATOR(<, __less)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/valarray:1199:1: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::valarray<_Tp>'
   14 |    cout<a[i]<<' ';
      |               ^~~
In file included from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:95,
                 from foo.cc:1:
/usr/include/c++/9/valarray:1199:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__less, std::_Constant, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__less, _Tp>::result_type> std::operator<(const typename std::valarray<_Tp>::value_type&, const std::valarray<_Tp>&)'
 1199 | _DEFINE_BINARY_OPERATOR(<, __less)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/valarray:1199:1: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   mismatched types 'const std::valarray<_Tp>' and 'int'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/bits/forward_list.h:1443:5: note: candidate: 'template<class _Tp, class _Alloc> bool std::operator<(const std::forward_list<_Tp, _Alloc>&, const std::forward_list<_Tp, _Alloc>&)'
 1443 |     operator<(const forward_list<_Tp, _Alloc>& __lx,
      |     ^~~~~~~~
/usr/include/c++/9/bits/forward_list.h:1443:5: note:   template argument deduction/substitution failed:
foo.cc:14:15: note:   'std::ostream' {aka 'std::basic_ostream<char>'} is not derived from 'const std::forward_list<_Tp, _Alloc>'
   14 |    cout<a[i]<<' ';
      |               ^~~
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:1:
/usr/include/c++/9/thread:290:3: note: candidate: 'bool std::operator<(std::thread::id, std::thread::id)'
  290 |   operator<(thread::id __x, thread::id __y) noexcept
      |   ^~~~~~~~
/usr/include/c++/9/thread:290:24: note:   no known conversion for argument 1 from 'std::ostream' {aka 'std::basic_ostream<char>'} to 'std::thread::id'
  290 |   operator<(thread::id __x, thread::id __y) noexcept
      |             ~~~~~~~~~~~^~~
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信息

递交者
类型
递交
题目
P1494 xf1-5排序与删除
语言
C++
递交时间
2022-05-10 20:13:59
评测时间
2022-05-10 20:13:59
评测机
分数
0
总耗时
0ms
峰值内存
0 Bytes