https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115839
Bug ID: 115839
Summary: Some common patterns in libstdc++-14 break many
libraries with clang in C++23
Product: gcc
Version: 14.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: jeanmichael.celerier at gmail dot com
Target Milestone: ---
Issue also posted to the LLVM bugtracker:
https://github.com/llvm/llvm-project/issues/97842
Some repros ; easily reproducible on an archlinux container.
Ex. 1: https://github.com/boostorg/container/issues/282
Repro:
```bash
$ docker run -v $PWD:/src -it archlinux:latest
$ pacman -Sy
$ pacman -S clang
$ echo '#include <boost/container/flat_map.hpp>
int main() {
boost::container::flat_map<int, int> f;
f[0];
}' > foo.cpp
$ clang++ foo.cpp -std=c++23 -I /src/boost_1_85_0
```
Ex. 2: https://github.com/martinus/unordered_dense/issues/119
Ex. 3:
```c++
#include <nlohmann/json.hpp>
void x(const char* s, int n)
{
nlohmann::json::parse(s, s + n);
}
```
cause errors such as :
```
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/tuple:956:36:
error: no matching function for call to 'get'
956 | return
__convertible<decltype(std::get<_Is>(std::declval<_UTuple>()))...>();
| ^~~~~~~~~~~~~
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/tuple:955:11:
note: in instantiation of function template specialization 'std::tuple<const
std::basic_string<char> &>::__convertible_from_tuple_like()::(anonymous
class)::operator()<0UL>' requested here
955 | return []<size_t... _Is>(index_sequence<_Is...>) {
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/tuple:1136:22:
note: in instantiation of function template specialization 'std::tuple<const
std::basic_string<char> &>::__convertible_from_tuple_like<const
std::basic_string<char> &>' requested here
1136 | constexpr explicit(!__convertible_from_tuple_like<_UTuple>())
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_map.h:514:38:
note: while substituting deduced template arguments into function template
'tuple' [with _UTuple = const key_type &]
514 | std::tuple<const
key_type&>(__k),
|
^
/usr/include/nlohmann/detail/input/json_sax.hpp:442:66: note: in instantiation
of member function 'std::map<std::basic_string<char>, nlohmann::basic_json<>,
std::less<void>>::operator[]' requested here
442 | object_element =
&(ref_stack.back()->m_value.object->operator[](val) = discarded);
| ^
/usr/include/nlohmann/detail/input/parser.hpp:219:56: note: in instantiation of
member function
'nlohmann::detail::json_sax_dom_callback_parser<nlohmann::basic_json<>>::key'
requested here
219 | if
(JSON_HEDLEY_UNLIKELY(!sax->key(m_lexer.get_string())))
| ^
/usr/include/nlohmann/detail/input/parser.hpp:98:13: note: in instantiation of
function template specialization
'nlohmann::detail::parser<nlohmann::basic_json<>,
nlohmann::detail::iterator_input_adapter<const char
*>>::sax_parse_internal<nlohmann::detail::json_sax_dom_callback_parser<nlohmann::basic_json<>>>'
requested here
98 | sax_parse_internal(&sdp);
| ^
/usr/include/nlohmann/json.hpp:4029:113: note: in instantiation of member
function 'nlohmann::detail::parser<nlohmann::basic_json<>,
nlohmann::detail::iterator_input_adapter<const char *>>::parse' requested here
4029 | parser(detail::input_adapter(std::move(first),
std::move(last)), cb, allow_exceptions, ignore_comments).parse(true, result);
|
^
/usr/include/nlohmann/json.hpp:5138:28: note: in instantiation of function
template specialization 'nlohmann::basic_json<>::parse<const char *>' requested
here
5138 | return nlohmann::json::parse(s, s + n);
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:122:5:
note: candidate template ignored: could not match 'tuple' against
'basic_string'
122 | get(tuple<_Elements...>& __t) noexcept;
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:126:5:
note: candidate template ignored: could not match 'tuple' against
'basic_string'
126 | get(const tuple<_Elements...>& __t) noexcept;
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:130:5:
note: candidate template ignored: could not match 'tuple' against
'basic_string'
130 | get(tuple<_Elements...>&& __t) noexcept;
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:134:5:
note: candidate template ignored: could not match 'tuple' against
'basic_string'
134 | get(const tuple<_Elements...>&& __t) noexcept;
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:138:5:
note: candidate template ignored: could not match 'array' against
'basic_string'
138 | get(array<_Tp, _Nm>&) noexcept;
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:142:5:
note: candidate template ignored: could not match 'array' against
'basic_string'
142 | get(array<_Tp, _Nm>&&) noexcept;
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:146:5:
note: candidate template ignored: could not match 'array' against
'basic_string'
146 | get(const array<_Tp, _Nm>&) noexcept;
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:150:5:
note: candidate template ignored: could not match 'array' against
'basic_string'
150 | get(const array<_Tp, _Nm>&&) noexcept;
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:1250:5:
note: candidate template ignored: could not match 'pair' against 'basic_string'
1250 | get(pair<_Tp1, _Tp2>& __in) noexcept
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:1255:5:
note: candidate template ignored: could not match 'pair' against 'basic_string'
1255 | get(pair<_Tp1, _Tp2>&& __in) noexcept
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:1260:5:
note: candidate template ignored: could not match 'pair' against 'basic_string'
1260 | get(const pair<_Tp1, _Tp2>& __in) noexcept
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:1265:5:
note: candidate template ignored: could not match 'pair' against 'basic_string'
1265 | get(const pair<_Tp1, _Tp2>&& __in) noexcept
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/ranges_util.h:444:5:
note: candidate template ignored: could not match 'subrange' against
'basic_string'
444 | get(const subrange<_It, _Sent, _Kind>& __r)
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/ranges_util.h:455:5:
note: candidate template ignored: could not match 'subrange' against
'basic_string'
455 | get(subrange<_It, _Sent, _Kind>&& __r)
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:1272:5:
note: candidate template ignored: invalid explicitly-specified argument for
template parameter '_Tp'
1272 | get(pair<_Tp, _Up>& __p) noexcept
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:1277:5:
note: candidate template ignored: invalid explicitly-specified argument for
template parameter '_Tp'
1277 | get(const pair<_Tp, _Up>& __p) noexcept
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:1282:5:
note: candidate template ignored: invalid explicitly-specified argument for
template parameter '_Tp'
1282 | get(pair<_Tp, _Up>&& __p) noexcept
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:1287:5:
note: candidate template ignored: invalid explicitly-specified argument for
template parameter '_Tp'
1287 | get(const pair<_Tp, _Up>&& __p) noexcept
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:1292:5:
note: candidate template ignored: invalid explicitly-specified argument for
template parameter '_Tp'
1292 | get(pair<_Up, _Tp>& __p) noexcept
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:1297:5:
note: candidate template ignored: invalid explicitly-specified argument for
template parameter '_Tp'
1297 | get(const pair<_Up, _Tp>& __p) noexcept
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:1302:5:
note: candidate template ignored: invalid explicitly-specified argument for
template parameter '_Tp'
1302 | get(pair<_Up, _Tp>&& __p) noexcept
| ^
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/14.1.1/../../../../include/c++/14.1.1/bits/stl_pair.h:1307:5:
note: candidate template ignored: invalid explicitly-specified argument for
template parameter '_Tp'
1307 | get(const pair<_Up, _Tp>&& __p) noexcept
| ^
1 warning and 1 error generated.
```
