https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121858
Bug ID: 121858
Summary: function_ref(nontype_t<__fn>, _Up&& __ref) did not
consider that _Up is a reference_wrapper
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: hewillk at gmail dot com
Target Milestone: ---
This constructor invokes the member pointer on a pointer to object _Up when _Fn
is a member pointer.
However, _Up can be a std::reference_wrapper because std::invoke supports
wrapping objects with std::ref. In this case, the call is ill-formed.
The following case is valid and should print hello:
#include <functional>
struct S { void f(); };
int main() {
S s;
auto sr = std::ref(s);
std::function_ref<void()> fr(std::nontype<&S::f>, sr);
fr();
}
https://godbolt.org/z/4P1Eo17oj
