https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67499
--- Comment #10 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
This is the current GCC output:
```
<source>: In function 'int main()':
<source>:5:13: error: no match for 'operator<<' (operand types are
'std::ostream' {aka 'std::basic_ostream<char>'} and 'foo')
5 | std::cout << bar;
| ~~~~~~~~~ ^~ ~~~
| | |
| | foo
| std::ostream {aka std::basic_ostream<char>}
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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&))
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:108:36:
note: no known conversion for argument 1 from 'foo' 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&))
| ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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&))
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:117:32:
note: no known conversion for argument 1 from 'foo' 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&))
| ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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&))
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:127:30:
note: no known conversion for argument 1 from 'foo' to 'std::ios_base&
(*)(std::ios_base&)'
127 | operator<<(ios_base& (*__pf) (ios_base&))
| ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:166:23:
note: no known conversion for argument 1 from 'foo' to 'long int'
166 | operator<<(long __n)
| ~~~~~^~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:170:32:
note: no known conversion for argument 1 from 'foo' to 'long unsigned int'
170 | operator<<(unsigned long __n)
| ~~~~~~~~~~~~~~^~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:174:23:
note: no known conversion for argument 1 from 'foo' to 'bool'
174 | operator<<(bool __n)
| ~~~~~^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:820,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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>::
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/bits/ostream.tcc:92:22:
note: no known conversion for argument 1 from 'foo' to 'short int'
92 | operator<<(short __n)
| ~~~~~~^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:181:33:
note: no known conversion for argument 1 from 'foo' to 'short unsigned int'
181 | operator<<(unsigned short __n)
| ~~~~~~~~~~~~~~~^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:820,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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>::
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/bits/ostream.tcc:106:20:
note: no known conversion for argument 1 from 'foo' to 'int'
106 | operator<<(int __n)
| ~~~~^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:192:31:
note: no known conversion for argument 1 from 'foo' to 'unsigned int'
192 | operator<<(unsigned int __n)
| ~~~~~~~~~~~~~^~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:201:28:
note: no known conversion for argument 1 from 'foo' to 'long long int'
201 | operator<<(long long __n)
| ~~~~~~~~~~^~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:205:37:
note: no known conversion for argument 1 from 'foo' to 'long long unsigned
int'
205 | operator<<(unsigned long long __n)
| ~~~~~~~~~~~~~~~~~~~^~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:220:25:
note: no known conversion for argument 1 from 'foo' to 'double'
220 | operator<<(double __f)
| ~~~~~~~^~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:224:24:
note: no known conversion for argument 1 from 'foo' to 'float'
224 | operator<<(float __f)
| ~~~~~~^~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:232:30:
note: no known conversion for argument 1 from 'foo' to 'long double'
232 | operator<<(long double __f)
| ~~~~~~~~~~~~^~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:245:30:
note: no known conversion for argument 1 from 'foo' to 'const void*'
245 | operator<<(const void* __p)
| ~~~~~~~~~~~~^~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:250:7:
note: candidate: 'std::basic_ostream<_CharT, _Traits>::__ostream_type&
std::basic_ostream<_CharT, _Traits>::operator<<(std::nullptr_t) [with _CharT =
char; _Traits = std::char_traits<char>; std::basic_ostream<_CharT,
_Traits>::__ostream_type = std::basic_ostream<char>; std::nullptr_t =
std::nullptr_t]'
250 | operator<<(nullptr_t)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:250:18:
note: no known conversion for argument 1 from 'foo' to 'std::nullptr_t'
250 | operator<<(nullptr_t)
| ^~~~~~~~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:820,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/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>::
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/bits/ostream.tcc:120:34:
note: no known conversion for argument 1 from 'foo' to
'std::basic_ostream<char>::__streambuf_type*' {aka
'std::basic_streambuf<char>*'}
120 | operator<<(__streambuf_type* __sbin)
| ~~~~~~~~~~~~~~~~~~^~~~~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/bits/basic_string.h:48,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/string:55,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/bits/locale_classes.h:40,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/bits/ios_base.h:41,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ios:42,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:38,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/string_view:667:5:
note: candidate: 'template<class _CharT, class _Traits>
std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT,
_Traits>&, std::basic_string_view<_CharT, _Traits>)'
667 | operator<<(basic_ostream<_CharT, _Traits>& __os,
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/string_view:667:5:
note: template argument deduction/substitution failed:
<source>:5:16: note: 'foo' is not derived from
'std::basic_string_view<_CharT, _Traits>'
5 | std::cout << bar;
| ^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/string:55,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/bits/locale_classes.h:40,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/bits/ios_base.h:41,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ios:42,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:38,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/bits/basic_string.h:3591:5:
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, _Allocator>&)'
3591 | operator<<(basic_ostream<_CharT, _Traits>& __os,
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/bits/basic_string.h:3591:5:
note: template argument deduction/substitution failed:
<source>:5:16: note: 'foo' is not derived from 'const
std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
5 | std::cout << bar;
| ^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/bits/ios_base.h:46,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ios:42,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:38,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/system_error:279:5:
note: candidate: 'template<class _CharT, class _Traits>
std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT,
_Traits>&, const std::error_code&)'
279 | operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code&
__e)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/system_error:279:5:
note: template argument deduction/substitution failed:
<source>:5:16: note: cannot convert 'bar' (type 'foo') to type 'const
std::error_code&'
5 | std::cout << bar;
| ^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:500:5:
note: candidate: 'template<class _CharT, class _Traits>
std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT,
_Traits>&, _CharT)'
500 | operator<<(basic_ostream<_CharT, _Traits>& __out, _CharT __c)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:500:5:
note: template argument deduction/substitution failed:
<source>:5:16: note: deduced conflicting types for parameter '_CharT' ('char'
and 'foo')
5 | std::cout << bar;
| ^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:505:5:
note: candidate: 'template<class _CharT, class _Traits>
std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT,
_Traits>&, char)'
505 | operator<<(basic_ostream<_CharT, _Traits>& __out, char __c)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:505:5:
note: template argument deduction/substitution failed:
<source>:5:16: note: cannot convert 'bar' (type 'foo') to type 'char'
5 | std::cout << bar;
| ^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:511:5:
note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>&
std::operator<<(std::basic_ostream<char, _Traits>&, char)'
511 | operator<<(basic_ostream<char, _Traits>& __out, char __c)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:511:5:
note: template argument deduction/substitution failed:
<source>:5:16: note: cannot convert 'bar' (type 'foo') to type 'char'
5 | std::cout << bar;
| ^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:517:5:
note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>&
std::operator<<(std::basic_ostream<char, _Traits>&, signed char)'
517 | operator<<(basic_ostream<char, _Traits>& __out, signed char __c)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:517:5:
note: template argument deduction/substitution failed:
<source>:5:16: note: cannot convert 'bar' (type 'foo') to type 'signed char'
5 | std::cout << bar;
| ^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:522:5:
note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>&
std::operator<<(std::basic_ostream<char, _Traits>&, unsigned char)'
522 | operator<<(basic_ostream<char, _Traits>& __out, unsigned char __c)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:522:5:
note: template argument deduction/substitution failed:
<source>:5:16: note: cannot convert 'bar' (type 'foo') to type 'unsigned
char'
5 | std::cout << bar;
| ^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:583:5:
note: candidate: 'template<class _CharT, class _Traits>
std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT,
_Traits>&, const _CharT*)'
583 | operator<<(basic_ostream<_CharT, _Traits>& __out, const _CharT*
__s)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:583:5:
note: template argument deduction/substitution failed:
<source>:5:16: note: mismatched types 'const _CharT*' and 'foo'
5 | std::cout << bar;
| ^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:820,
from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/bits/ostream.tcc:302:5:
note: candidate: 'template<class _CharT, class _Traits>
std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT,
_Traits>&, const char*)'
302 | operator<<(basic_ostream<_CharT, _Traits>& __out, const char* __s)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/bits/ostream.tcc:302:5:
note: template argument deduction/substitution failed:
<source>:5:16: note: cannot convert 'bar' (type 'foo') to type 'const char*'
5 | std::cout << bar;
| ^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:600:5:
note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>&
std::operator<<(std::basic_ostream<char, _Traits>&, const char*)'
600 | operator<<(basic_ostream<char, _Traits>& __out, const char* __s)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:600:5:
note: template argument deduction/substitution failed:
<source>:5:16: note: cannot convert 'bar' (type 'foo') to type 'const char*'
5 | std::cout << bar;
| ^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:613:5:
note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>&
std::operator<<(std::basic_ostream<char, _Traits>&, const signed char*)'
613 | operator<<(basic_ostream<char, _Traits>& __out, const signed char*
__s)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:613:5:
note: template argument deduction/substitution failed:
<source>:5:16: note: cannot convert 'bar' (type 'foo') to type 'const signed
char*'
5 | std::cout << bar;
| ^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:618:5:
note: candidate: 'template<class _Traits> std::basic_ostream<char, _Traits>&
std::operator<<(std::basic_ostream<char, _Traits>&, const unsigned char*)'
618 | operator<<(basic_ostream<char, _Traits>& __out, const unsigned
char* __s)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:618:5:
note: template argument deduction/substitution failed:
<source>:5:16: note: cannot convert 'bar' (type 'foo') to type 'const
unsigned char*'
5 | std::cout << bar;
| ^~~
In file included from
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/iostream:39,
from <source>:1:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:741:5:
note: candidate: 'template<class _Ostream, class _Tp> _Ostream&&
std::operator<<(_Ostream&&, const _Tp&)'
741 | operator<<(_Ostream&& __os, const _Tp& __x)
| ^~~~~~~~
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:741:5:
note: template argument deduction/substitution failed:
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream: In
substitution of 'template<class _Ostream, class _Tp> _Ostream&&
std::operator<<(_Ostream&&, const _Tp&) [with _Ostream =
std::basic_ostream<char>&; _Tp = foo]':
<source>:5:16: required from here
/opt/compiler-explorer/gcc-trunk-20210823/include/c++/12.0.0/ostream:741:5:
error: no type named 'type' in 'struct std::enable_if<false, void>'
```
