foo.cc: In function 'void Output(std::set<WC>&)':
foo.cc:19:7: error: no match for 'operator<<' (operand types are 'std::ostream' {aka 'std::basic_ostream<char>'} and 'const WC')
19 | cout<<*it<<" ";
| ~~~~^~~~~
| | |
| | const WC
| std::ostream {aka std::basic_ostream<char>}
In file included from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/ostream:108:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>::__ostream_type& (*)(std::basic_ostream<_CharT, _Traits>::__ostream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]'
108 | operator<<(__ostream_type& (*__pf)(__ostream_type&))
| ^~~~~~~~
/usr/include/c++/9/ostream:108:36: note: no known conversion for argument 1 from 'const WC' to 'std::basic_ostream<char>::__ostream_type& (*)(std::basic_ostream<char>::__ostream_type&)' {aka 'std::basic_ostream<char>& (*)(std::basic_ostream<char>&)'}
108 | operator<<(__ostream_type& (*__pf)(__ostream_type&))
| ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/ostream:117:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>::__ios_type& (*)(std::basic_ostream<_CharT, _Traits>::__ios_type&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>; std::basic_ostream<_CharT, _Traits>::__ios_type = std::basic_ios<char>]'
117 | operator<<(__ios_type& (*__pf)(__ios_type&))
| ^~~~~~~~
/usr/include/c++/9/ostream:117:32: note: no known conversion for argument 1 from 'const WC' to 'std::basic_ostream<char>::__ios_type& (*)(std::basic_ostream<char>::__ios_type&)' {aka 'std::basic_ios<char>& (*)(std::basic_ios<char>&)'}
117 | operator<<(__ios_type& (*__pf)(__ios_type&))
| ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
/usr/include/c++/9/ostream:127:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(std::ios_base& (*)(std::ios_base&)) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]'
127 | operator<<(ios_base& (*__pf) (ios_base&))
| ^~~~~~~~
/usr/include/c++/9/ostream:127:30: note: no known conversion for argument 1 from 'const WC' to 'std::ios_base& (*)(std::ios_base&)'
127 | operator<<(ios_base& (*__pf) (ios_base&))
| ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
/usr/include/c++/9/ostream:166:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]'
166 | operator<<(long __n)
| ^~~~~~~~
/usr/include/c++/9/ostream:166:23: note: no known conversion for argument 1 from 'const WC' to 'long int'
166 | operator<<(long __n)
| ~~~~~^~~
/usr/include/c++/9/ostream:170:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]'
170 | operator<<(unsigned long __n)
| ^~~~~~~~
/usr/include/c++/9/ostream:170:32: note: no known conversion for argument 1 from 'const WC' to 'long unsigned int'
170 | operator<<(unsigned long __n)
| ~~~~~~~~~~~~~~^~~
/usr/include/c++/9/ostream:174:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(bool) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]'
174 | operator<<(bool __n)
| ^~~~~~~~
/usr/include/c++/9/ostream:174:23: note: no known conversion for argument 1 from 'const WC' to 'bool'
174 | operator<<(bool __n)
| ~~~~~^~~
In file included from /usr/include/c++/9/ostream:702,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/ostream.tcc:91:5: note: candidate: 'std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(short int) [with _CharT = char; _Traits = std::char_traits<char>]'
91 | basic_ostream<_CharT, _Traits>::
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/ostream.tcc:92:22: note: no known conversion for argument 1 from 'const WC' to 'short int'
92 | operator<<(short __n)
| ~~~~~~^~~
In file included from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/ostream:181:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(short unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]'
181 | operator<<(unsigned short __n)
| ^~~~~~~~
/usr/include/c++/9/ostream:181:33: note: no known conversion for argument 1 from 'const WC' to 'short unsigned int'
181 | operator<<(unsigned short __n)
| ~~~~~~~~~~~~~~~^~~
In file included from /usr/include/c++/9/ostream:702,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/ostream.tcc:105:5: note: candidate: 'std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(int) [with _CharT = char; _Traits = std::char_traits<char>]'
105 | basic_ostream<_CharT, _Traits>::
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/ostream.tcc:106:20: note: no known conversion for argument 1 from 'const WC' to 'int'
106 | operator<<(int __n)
| ~~~~^~~
In file included from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/ostream:192:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]'
192 | operator<<(unsigned int __n)
| ^~~~~~~~
/usr/include/c++/9/ostream:192:31: note: no known conversion for argument 1 from 'const WC' to 'unsigned int'
192 | operator<<(unsigned int __n)
| ~~~~~~~~~~~~~^~~
/usr/include/c++/9/ostream:201:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long long int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]'
201 | operator<<(long long __n)
| ^~~~~~~~
/usr/include/c++/9/ostream:201:28: note: no known conversion for argument 1 from 'const WC' to 'long long int'
201 | operator<<(long long __n)
| ~~~~~~~~~~^~~
/usr/include/c++/9/ostream:205:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long long unsigned int) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]'
205 | operator<<(unsigned long long __n)
| ^~~~~~~~
/usr/include/c++/9/ostream:205:37: note: no known conversion for argument 1 from 'const WC' to 'long long unsigned int'
205 | operator<<(unsigned long long __n)
| ~~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/9/ostream:220:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(double) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]'
220 | operator<<(double __f)
| ^~~~~~~~
/usr/include/c++/9/ostream:220:25: note: no known conversion for argument 1 from 'const WC' to 'double'
220 | operator<<(double __f)
| ~~~~~~~^~~
/usr/include/c++/9/ostream:224:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(float) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]'
224 | operator<<(float __f)
| ^~~~~~~~
/usr/include/c++/9/ostream:224:24: note: no known conversion for argument 1 from 'const WC' to 'float'
224 | operator<<(float __f)
| ~~~~~~^~~
/usr/include/c++/9/ostream:232:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(long double) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]'
232 | operator<<(long double __f)
| ^~~~~~~~
/usr/include/c++/9/ostream:232:30: note: no known conversion for argument 1 from 'const WC' to 'long double'
232 | operator<<(long double __f)
| ~~~~~~~~~~~~^~~
/usr/include/c++/9/ostream:245:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type& std::basic_ostream<_CharT, _Traits>::operator<<(const void*) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__ostream_type = std::basic_ostream<char>]'
245 | operator<<(const void* __p)
| ^~~~~~~~
/usr/include/c++/9/ostream:245:30: note: no known conversion for argument 1 from 'const WC' to 'const void*'
245 | operator<<(const void* __p)
| ~~~~~~~~~~~~^~~
In file included from /usr/include/c++/9/ostream:702,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/ostream.tcc:119:5: note: candidate: 'std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>::__streambuf_type*) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT, _Traits>::__streambuf_type = std::basic_streambuf<char>]'
119 | basic_ostream<_CharT, _Traits>::
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/9/bits/ostream.tcc:120:34: note: no known conversion for argument 1 from 'const WC' to 'std::basic_ostream<char>::__streambuf_type*' {aka 'std::basic_streambuf<char>*'}
120 | operator<<(__streambuf_type* __sbin)
| ~~~~~~~~~~~~~~~~~~^~~~~~
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/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/basic_string.h:6419:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
6419 | operator<<(basic_ostream<_CharT, _Traits>& __os,
| ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6419:5: note: template argument deduction/substitution failed:
foo.cc:19:10: note: 'const WC' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
19 | cout<<*it<<" ";
| ^~
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/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/system_error:217:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const std::error_code&)'
217 | operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code& __e)
| ^~~~~~~~
/usr/include/c++/9/system_error:217:5: note: template argument deduction/substitution failed:
foo.cc:19:9: note: cannot convert 'it.std::_Rb_tree_const_iterator<WC>::operator*()' (type 'const WC') to type 'const std::error_code&'
19 | cout<<*it<<" ";
| ^~~
In file included from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/ostream:506:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, _CharT)'
506 | operator<<(basic_ostream<_CharT, _Traits>& __out, _CharT __c)
| ^~~~~~~~
/usr/include/c++/9/ostream:506:5: note: template argument deduction/substitution failed:
foo.cc:19:10: note: deduced conflicting types for parameter '_CharT' ('char' and 'WC')
19 | cout<<*it<<" ";
| ^~
In file included from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/ostream:511:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, char)'
511 | operator<<(basic_ostream<_CharT, _Traits>& __out, char __c)
| ^~~~~~~~
/usr/include/c++/9/ostream:511:5: note: template argument deduction/substitution failed:
foo.cc:19:9: note: cannot convert 'it.std::_Rb_tree_const_iterator<WC>::operator*()' (type 'const WC') to type 'char'
19 | cout<<*it<<" ";
| ^~~
In file included from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/ostream:517:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, char)'
517 | operator<<(basic_ostream<char, _Traits>& __out, char __c)
| ^~~~~~~~
/usr/include/c++/9/ostream:517:5: note: template argument deduction/substitution failed:
foo.cc:19:9: note: cannot convert 'it.std::_Rb_tree_const_iterator<WC>::operator*()' (type 'const WC') to type 'char'
19 | cout<<*it<<" ";
| ^~~
In file included from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/ostream:523:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, signed char)'
523 | operator<<(basic_ostream<char, _Traits>& __out, signed char __c)
| ^~~~~~~~
/usr/include/c++/9/ostream:523:5: note: template argument deduction/substitution failed:
foo.cc:19:9: note: cannot convert 'it.std::_Rb_tree_const_iterator<WC>::operator*()' (type 'const WC') to type 'signed char'
19 | cout<<*it<<" ";
| ^~~
In file included from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/ostream:528:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, unsigned char)'
528 | operator<<(basic_ostream<char, _Traits>& __out, unsigned char __c)
| ^~~~~~~~
/usr/include/c++/9/ostream:528:5: note: template argument deduction/substitution failed:
foo.cc:19:9: note: cannot convert 'it.std::_Rb_tree_const_iterator<WC>::operator*()' (type 'const WC') to type 'unsigned char'
19 | cout<<*it<<" ";
| ^~~
In file included from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/ostream:548:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const _CharT*)'
548 | operator<<(basic_ostream<_CharT, _Traits>& __out, const _CharT* __s)
| ^~~~~~~~
/usr/include/c++/9/ostream:548:5: note: template argument deduction/substitution failed:
foo.cc:19:10: note: mismatched types 'const _CharT*' and 'WC'
19 | cout<<*it<<" ";
| ^~
In file included from /usr/include/c++/9/ostream:702,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/ostream.tcc:321:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const char*)'
321 | operator<<(basic_ostream<_CharT, _Traits>& __out, const char* __s)
| ^~~~~~~~
/usr/include/c++/9/bits/ostream.tcc:321:5: note: template argument deduction/substitution failed:
foo.cc:19:9: note: cannot convert 'it.std::_Rb_tree_const_iterator<WC>::operator*()' (type 'const WC') to type 'const char*'
19 | cout<<*it<<" ";
| ^~~
In file included from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/ostream:565:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const char*)'
565 | operator<<(basic_ostream<char, _Traits>& __out, const char* __s)
| ^~~~~~~~
/usr/include/c++/9/ostream:565:5: note: template argument deduction/substitution failed:
foo.cc:19:9: note: cannot convert 'it.std::_Rb_tree_const_iterator<WC>::operator*()' (type 'const WC') to type 'const char*'
19 | cout<<*it<<" ";
| ^~~
In file included from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/ostream:578:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const signed char*)'
578 | operator<<(basic_ostream<char, _Traits>& __out, const signed char* __s)
| ^~~~~~~~
/usr/include/c++/9/ostream:578:5: note: template argument deduction/substitution failed:
foo.cc:19:9: note: cannot convert 'it.std::_Rb_tree_const_iterator<WC>::operator*()' (type 'const WC') to type 'const signed char*'
19 | cout<<*it<<" ";
| ^~~
In file included from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/ostream:583:5: note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const unsigned char*)'
583 | operator<<(basic_ostream<char, _Traits>& __out, const unsigned char* __s)
| ^~~~~~~~
/usr/include/c++/9/ostream:583:5: note: template argument deduction/substitution failed:
foo.cc:19:9: note: cannot convert 'it.std::_Rb_tree_const_iterator<WC>::operator*()' (type 'const WC') to type 'const unsigned char*'
19 | cout<<*it<<" ";
| ^~~
In file included from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/ostream:691:5: note: candidate: 'template<class _Ostream, class _Tp> typename std::enable_if<std::__and_<std::__not_<std::is_lvalue_reference<_Tp> >, std::__is_convertible_to_basic_ostream<_Ostream>, std::__is_insertable<typename std::__is_convertible_to_basic_ostream<_Tp>::__ostream_type, const _Tp&, void> >::value, typename std::__is_convertible_to_basic_ostream<_Tp>::__ostream_type>::type std::operator<<(_Ostream&&, const _Tp&)'
691 | operator<<(_Ostream&& __os, const _Tp& __x)
| ^~~~~~~~
/usr/include/c++/9/ostream:691:5: note: template argument deduction/substitution failed:
/usr/include/c++/9/ostream: In substitution of 'template<class _Ostream, class _Tp> typename std::enable_if<std::__and_<std::__not_<std::is_lvalue_reference<_Tp> >, std::__is_convertible_to_basic_ostream<_Ostream>, std::__is_insertable<typename std::__is_convertible_to_basic_ostream<_Tp>::__ostream_type, const _Tp&, void> >::value, typename std::__is_convertible_to_basic_ostream<_Tp>::__ostream_type>::type std::operator<<(_Ostream&&, const _Tp&) [with _Ostream = std::basic_ostream<char>&; _Tp = WC]':
foo.cc:19:10: required from here
/usr/include/c++/9/ostream:691:5: error: no type named 'type' in 'struct std::enable_if<false, std::basic_ostream<char>&>'
foo.cc:11:18: note: candidate: 'std::ostream& operator<<(std::ostream&, WC&)' <near match>
11 | friend ostream& operator<<(ostream & out, WC &wc)
| ^~~~~~~~
foo.cc:11:18: note: conversion of argument 2 would be ill-formed:
foo.cc:19:9: error: binding reference of type 'WC&' to 'const WC' discards qualifiers
19 | cout<<*it<<" ";
| ^~~
foo.cc: In function 'void Test()':
foo.cc:36:8: error: increment of member 'WC::cnt' in read-only object
36 | it->cnt++;
| ~~~~^~~
In file included from /usr/include/c++/9/string:48,
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/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/stl_function.h: In instantiation of 'bool std::less<_Tp>::operator()(const _Tp&, const _Tp&) const [with _Tp = WC]':
/usr/include/c++/9/bits/stl_tree.h:2564:8: required from 'std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::find(const _Key&) [with _Key = WC; _Val = WC; _KeyOfValue = std::_Identity<WC>; _Compare = std::less<WC>; _Alloc = std::allocator<WC>; std::_Rb_tree<_Key, _Val, _KeyOfValue, _Compare, _Alloc>::iterator = std::_Rb_tree_iterator<WC>]'
/usr/include/c++/9/bits/stl_set.h:795:29: required from 'std::set<_Key, _Compare, _Alloc>::iterator std::set<_Key, _Compare, _Alloc>::find(const key_type&) [with _Key = WC; _Compare = std::less<WC>; _Alloc = std::allocator<WC>; std::set<_Key, _Compare, _Alloc>::iterator = std::_Rb_tree_const_iterator<WC>; std::set<_Key, _Compare, _Alloc>::key_type = WC]'
foo.cc:32:37: required from here
/usr/include/c++/9/bits/stl_function.h:386:20: error: no match for 'operator<' (operand types are 'const WC' and 'const WC')
386 | { return __x < __y; }
| ~~~~^~~~~
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/ostream:38,
from /usr/include/c++/9/iostream:39,
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:
In file included from /usr/include/c++/9/string:48,
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/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/stl_function.h:386:20: note: 'const WC' is not derived from 'const std::pair<_T1, _T2>'
386 | { return __x < __y; }
| ~~~~^~~~~
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/ostream:38,
from /usr/include/c++/9/iostream:39,
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:
In file included from /usr/include/c++/9/string:48,
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/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/stl_function.h:386:20: note: 'const WC' is not derived from 'const std::reverse_iterator<_Iterator>'
386 | { return __x < __y; }
| ~~~~^~~~~
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/ostream:38,
from /usr/include/c++/9/iostream:39,
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:
In file included from /usr/include/c++/9/string:48,
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/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/stl_function.h:386:20: note: 'const WC' is not derived from 'const std::reverse_iterator<_Iterator>'
386 | { return __x < __y; }
| ~~~~^~~~~
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/ostream:38,
from /usr/include/c++/9/iostream:39,
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:
In file included from /usr/include/c++/9/string:48,
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/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/stl_function.h:386:20: note: 'const WC' is not derived from 'const std::move_iterator<_IteratorL>'
386 | { return __x < __y; }
| ~~~~^~~~~
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/ostream:38,
from /usr/include/c++/9/iostream:39,
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:
In file included from /usr/include/c++/9/string:48,
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/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/stl_function.h:386:20: note: 'const WC' is not derived from 'const std::move_iterator<_IteratorL>'
386 | { return __x < __y; }
| ~~~~^~~~~
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/ostream:38,
from /usr/include/c++/9/iostream:39,
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:
In file included from /usr/include/c++/9/string:48,
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/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/stl_function.h:386:20: note: 'const WC' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
386 | { return __x < __y; }
| ~~~~^~~~~
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/ostream:38,
from /usr/include/c++/9/iostream:39,
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:
In file included from /usr/include/c++/9/string:48,
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/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/stl_function.h:386:20: note: 'const WC' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
386 | { return __x < __y; }
| ~~~~^~~~~
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/ostream:38,
from /usr/include/c++/9/iostream:39,
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:
In file included from /usr/include/c++/9/string:48,
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/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/stl_function.h:386:20: note: mismatched types 'const _CharT*' and 'WC'
386 | { return __x < __y; }
| ~~~~^~~~~
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/ostream:38,
from /usr/include/c++/9/iostream:39,
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 'const WC' 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 'const WC' to 'const std::error_condition&'
282 | operator<(const error_condition& __lhs,
| ~~~~~~~~~~~~~~~~~~~~~~~^~~~~
In file included from /usr/include/c++/9/set:61,
from foo.cc:4:
/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:
In file included from /usr/include/c++/9/string:48,
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/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/stl_function.h:386:20: note: 'const WC' is not derived from 'const std::set<_Key, _Compare, _Alloc>'
386 | { return __x < __y; }
| ~~~~^~~~~
In file included from /usr/include/c++/9/set:62,
from foo.cc:4:
/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:
In file included from /usr/include/c++/9/string:48,
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/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/stl_function.h:386:20: note: 'const WC' is not derived from 'const std::multiset<_Key, _Compare, _Alloc>'
386 | { return __x < __y; }
| ~~~~^~~~~