https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120764
Bug ID: 120764
Summary: redefinition errors when using certain std headers in
GMF
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: furyusss at yahoo dot fr
Target Milestone: ---
cat std.cpp
module;
#include <chrono>
// first thing after the Global module fragment must be a module command
export module std;
export void fun(std::string_view) {
}
cat main.cpp
import std;
#include <print>
int main() {
}
g++ -std=c++23 -fmodules-ts -c std.cpp
g++ -std=c++23 -fmodules-ts main.cpp -o main
In file included from /usr/include/c++/15/concepts:48,
from /usr/include/c++/15/compare:42,
from /usr/include/c++/15/array:40,
from /usr/include/c++/15/format:45,
from /usr/include/c++/15/print:43,
from main.cpp:3:
/usr/include/c++/15/type_traits:94:28: error: template definition of
non-template ‘constexpr const _Tp std::integral_constant<_Tp, __v>::value’
[-Wtemplate-body]
94 | static constexpr _Tp value = __v;
| ^~~~~
/usr/include/c++/15/type_traits:95:29: error: template definition of
non-template ‘using std::integral_constant<_Tp, __v>::value_type = _Tp’
[-Wtemplate-body]
95 | using value_type = _Tp;
| ^
/usr/include/c++/15/type_traits:96:47: error: template definition of
non-template ‘using std::integral_constant<_Tp, __v>::type = struct
std::integral_constant<_Tp, __v>’ [-Wtemplate-body]
96 | using type = integral_constant<_Tp, __v>;
| ^
/usr/include/c++/15/type_traits:97:45: error: template definition of
non-template ‘constexpr std::integral_constant<_Tp, __v>::operator value_type()
const’ [-Wtemplate-body]
97 | constexpr operator value_type() const noexcept { return value; }
| ^~~~~~~~
/usr/include/c++/15/type_traits:100:47: error: template definition of
non-template ‘constexpr std::integral_constant<_Tp, __v>::value_type
std::integral_constant<_Tp, __v>::operator()() const’ [-Wtemplate-body]
100 | constexpr value_type operator()() const noexcept { return value;
}
| ^~~~~~~~
/usr/include/c++/15/type_traits:219:27: error: redefinition of ‘template<class
... _Bn> constexpr const bool std::__and_v’
219 | inline constexpr bool __and_v = __and_<_Bn...>::value;
| ^~~~~~~
In file included from /usr/include/c++/15/ratio:41,
from /usr/include/c++/15/bits/chrono.h:39,
from /usr/include/c++/15/chrono:45,
from std.cpp:3,
of module std, imported at main.cpp:1:
/usr/include/c++/15/type_traits:219:27: note: ‘template<class ... _Bn>
constexpr const bool std::__and_v<_Bn ...>’ previously declared here
219 | inline constexpr bool __and_v = __and_<_Bn...>::value;
| ^~~~~~~
g++ -v
gcc version 15.0.1 20250404 (experimental) [master r15-9193-g08e803aa9be]
(Ubuntu 15-20250404-0ubuntu1)
This seems similar to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114600.
