foo.cc:6:8: warning: character constant too long for its type
6 | if(a=='ABCBA')
| ^~~~~~~
foo.cc: In function 'int main()':
foo.cc:6:6: error: no match for 'operator==' (operand types are 'std::string' {aka 'std::__cxx11::basic_string<char>'} and 'int')
6 | if(a=='ABCBA')
| ~^~~~~~~~~
| | |
| | int
| std::string {aka std::__cxx11::basic_string<char>}
In file included from /usr/include/c++/9/iosfwd:40,
from /usr/include/c++/9/ios:38,
from /usr/include/c++/9/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/postypes.h:222:5: note: candidate: 'template<class _StateT> bool std::operator==(const std::fpos<_StateT>&, const std::fpos<_StateT>&)'
222 | operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
| ^~~~~~~~
/usr/include/c++/9/bits/postypes.h:222:5: note: template argument deduction/substitution failed:
foo.cc:6:8: note: 'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::fpos<_StateT>'
6 | if(a=='ABCBA')
| ^~~~~~~
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:448:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator==(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)'
448 | operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
| ^~~~~~~~
/usr/include/c++/9/bits/stl_pair.h:448:5: note: template argument deduction/substitution failed:
foo.cc:6:8: note: 'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::pair<_T1, _T2>'
6 | if(a=='ABCBA')
| ^~~~~~~
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:325:5: note: candidate: 'template<class _Iterator> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)'
325 | operator==(const reverse_iterator<_Iterator>& __x,
| ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:325:5: note: template argument deduction/substitution failed:
foo.cc:6:8: note: 'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::reverse_iterator<_Iterator>'
6 | if(a=='ABCBA')
| ^~~~~~~
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:363:5: note: candidate: 'template<class _IteratorL, class _IteratorR> bool std::operator==(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)'
363 | operator==(const reverse_iterator<_IteratorL>& __x,
| ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:363:5: note: template argument deduction/substitution failed:
foo.cc:6:8: note: 'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::reverse_iterator<_Iterator>'
6 | if(a=='ABCBA')
| ^~~~~~~
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:1136:5: note: candidate: 'template<class _IteratorL, class _IteratorR> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)'
1136 | operator==(const move_iterator<_IteratorL>& __x,
| ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:1136:5: note: template argument deduction/substitution failed:
foo.cc:6:8: note: 'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::move_iterator<_IteratorL>'
6 | if(a=='ABCBA')
| ^~~~~~~
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:1142:5: note: candidate: 'template<class _Iterator> bool std::operator==(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)'
1142 | operator==(const move_iterator<_Iterator>& __x,
| ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:1142:5: note: template argument deduction/substitution failed:
foo.cc:6:8: note: 'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::move_iterator<_IteratorL>'
6 | if(a=='ABCBA')
| ^~~~~~~
In file included from /usr/include/c++/9/string:41,
from /usr/include/c++/9/bits/locale_classes.h:40,
from /usr/include/c++/9/bits/ios_base.h:41,
from /usr/include/c++/9/ios:42,
from /usr/include/c++/9/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/allocator.h:167:5: note: candidate: 'template<class _T1, class _T2> bool std::operator==(const std::allocator<_CharT>&, const std::allocator<_T2>&)'
167 | operator==(const allocator<_T1>&, const allocator<_T2>&)
| ^~~~~~~~
/usr/include/c++/9/bits/allocator.h:167:5: note: template argument deduction/substitution failed:
foo.cc:6:8: note: 'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::allocator<_CharT>'
6 | if(a=='ABCBA')
| ^~~~~~~
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:6144:5: 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>&)'
6144 | operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
| ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6144:5: note: template argument deduction/substitution failed:
foo.cc:6:8: note: mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>' and 'int'
6 | if(a=='ABCBA')
| ^~~~~~~
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:6152:5: note: candidate: 'template<class _CharT> typename __gnu_cxx::__enable_if<std::__is_char<_Tp>::__value, bool>::__type std::operator==(const std::__cxx11::basic_string<_CharT>&, const std::__cxx11::basic_string<_CharT>&)'
6152 | operator==(const basic_string<_CharT>& __lhs,
| ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6152:5: note: template argument deduction/substitution failed:
foo.cc:6:8: note: mismatched types 'const std::__cxx11::basic_string<_CharT>' and 'int'
6 | if(a=='ABCBA')
| ^~~~~~~
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:6166:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
6166 | operator==(const _CharT* __lhs,
| ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6166:5: note: template argument deduction/substitution failed:
foo.cc:6:8: note: mismatched types 'const _CharT*' and 'std::__cxx11::basic_string<char>'
6 | if(a=='ABCBA')
| ^~~~~~~
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:6178:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator==(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)'
6178 | operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
| ^~~~~~~~
/usr/include/c++/9/bits/basic_string.h:6178:5: note: template argument deduction/substitution failed:
foo.cc:6:8: note: mismatched types 'const _CharT*' and 'int'
6 | if(a=='ABCBA')
| ^~~~~~~
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:292:3: note: candidate: 'bool std::operator==(const std::error_code&, const std::error_code&)'
292 | operator==(const error_code& __lhs, const error_code& __rhs) noexcept
| ^~~~~~~~
/usr/include/c++/9/system_error:292:32: note: no known conversion for argument 1 from 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'const std::error_code&'
292 | operator==(const error_code& __lhs, const error_code& __rhs) noexcept
| ~~~~~~~~~~~~~~~~~~^~~~~
/usr/include/c++/9/system_error:297:3: note: candidate: 'bool std::operator==(const std::error_code&, const std::error_condition&)'
297 | operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
| ^~~~~~~~
/usr/include/c++/9/system_error:297:32: note: no known conversion for argument 1 from 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'const std::error_code&'
297 | operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
| ~~~~~~~~~~~~~~~~~~^~~~~
/usr/include/c++/9/system_error:304:3: note: candidate: 'bool std::operator==(const std::error_condition&, const std::error_code&)'
304 | operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
| ^~~~~~~~
/usr/include/c++/9/system_error:304:37: note: no known conversion for argument 1 from 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'const std::error_condition&'
304 | operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
| ~~~~~~~~~~~~~~~~~~~~~~~^~~~~
/usr/include/c++/9/system_error:311:3: note: candidate: 'bool std::operator==(const std::error_condition&, const std::error_condition&)'
311 | operator==(const error_condition& __lhs,
| ^~~~~~~~
/usr/include/c++/9/system_error:311:37: note: no known conversion for argument 1 from 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'const std::error_condition&'
311 | operator==(const error_condition& __lhs,
| ~~~~~~~~~~~~~~~~~~~~~~~^~~~~
In file included from /usr/include/c++/9/bits/locale_facets.h:48,
from /usr/include/c++/9/bits/basic_ios.h:37,
from /usr/include/c++/9/ios:44,
from /usr/include/c++/9/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/streambuf_iterator.h:208:5: note: candidate: 'template<class _CharT, class _Traits> bool std::operator==(const std::istreambuf_iterator<_CharT, _Traits>&, const std::istreambuf_iterator<_CharT, _Traits>&)'
208 | operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
| ^~~~~~~~
/usr/include/c++/9/bits/streambuf_iterator.h:208:5: note: template argument deduction/substitution failed:
foo.cc:6:8: note: 'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::istreambuf_iterator<_CharT, _Traits>'
6 | if(a=='ABCBA')
| ^~~~~~~
In file included from /usr/include/c++/9/string:41,
from /usr/include/c++/9/bits/locale_classes.h:40,
from /usr/include/c++/9/bits/ios_base.h:41,
from /usr/include/c++/9/ios:42,
from /usr/include/c++/9/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/bits/allocator.h:155:7: note: candidate: 'bool std::operator==(const std::allocator<char>&, const std::allocator<char>&)'
155 | operator==(const allocator&, const allocator&) _GLIBCXX_NOTHROW
| ^~~~~~~~
/usr/include/c++/9/bits/allocator.h:155:18: note: no known conversion for argument 1 from 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'const std::allocator<char>&'
155 | operator==(const allocator&, const allocator&) _GLIBCXX_NOTHROW
| ^~~~~~~~~~~~~~~~
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:883:5: note: candidate: 'template<class _IteratorL, class _IteratorR, class _Container> bool __gnu_cxx::operator==(const __gnu_cxx::__normal_iterator<_IteratorL, _Container>&, const __gnu_cxx::__normal_iterator<_IteratorR, _Container>&)'
883 | operator==(const __normal_iterator<_IteratorL, _Container>& __lhs,
| ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:883:5: note: template argument deduction/substitution failed:
foo.cc:6:8: note: 'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const __gnu_cxx::__normal_iterator<_IteratorL, _Container>'
6 | if(a=='ABCBA')
| ^~~~~~~
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:890:5: note: candidate: 'template<class _Iterator, class _Container> bool __gnu_cxx::operator==(const __gnu_cxx::__normal_iterator<_Iterator, _Container>&, const __gnu_cxx::__normal_iterator<_Iterator, _Container>&)'
890 | operator==(const __normal_iterator<_Iterator, _Container>& __lhs,
| ^~~~~~~~
/usr/include/c++/9/bits/stl_iterator.h:890:5: note: template argument deduction/substitution failed:
foo.cc:6:8: note: 'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const __gnu_cxx::__normal_iterator<_Iterator, _Container>'
6 | if(a=='ABCBA')
| ^~~~~~~
In file included from /usr/include/x86_64-linux-gnu/c++/9/bits/c++allocator.h:33,
from /usr/include/c++/9/bits/allocator.h:46,
from /usr/include/c++/9/string:41,
from /usr/include/c++/9/bits/locale_classes.h:40,
from /usr/include/c++/9/bits/ios_base.h:41,
from /usr/include/c++/9/ios:42,
from /usr/include/c++/9/ostream:38,
from /usr/include/c++/9/iostream:39,
from foo.cc:1:
/usr/include/c++/9/ext/new_allocator.h:166:2: note: candidate: 'template<class _Up> bool __gnu_cxx::operator==(const __gnu_cxx::new_allocator<char>&, const __gnu_cxx::new_allocator<_Tp>&)'
166 | operator==(const new_allocator&, const new_allocator<_Up>&)
| ^~~~~~~~
/usr/include/c++/9/ext/new_allocator.h:166:2: note: template argument deduction/substitution failed:
foo.cc:6:8: note: mismatched types 'const __gnu_cxx::new_allocator<_Tp>' and 'int'
6 | if(a=='ABCBA')
| ^~~~~~~
