This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 118e. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
2025-11-05
[Accepted as a DR at the February, 2023 meeting.]
According to 9.12 [dcl.link] paragraph 5,
A C language linkage is ignored in determining the languagelinkage of class members, friend functions with atrailingrequires-clause, and the function type ofclass member functions.
It doesn't make sense that static member functions shouldbehave like non-static member functions in this regard:
extern "C" { struct A { static void f(); constexpr static void (*p)()=f; // error: must point to a function whose type has C language linkage }; }Suggested resolution:
Change 9.12 [dcl.link] paragraph 5 as follows:
A C language linkage is ignored in determining the languagelinkage of class members, friend functions with atrailingrequires-clause, and the function type ofnon-static class member functions.
Notes from the August, 2021 teleconference:
There was some question as to whether a linkagespecification should affect the language linkage of anyfunction declarators within class scope. The question wasalso raised as to whether some non-typedef syntax should beavailable for affecting language linkage, which would be aquestion for EWG.
Proposed resolution (approved by CWG 2022-11-10):
Change 9.12 [dcl.link] paragraph 5 as follows:
A C language linkage is ignored in determining the languagelinkage of class members, friend functions with atrailingrequires-clause, and the function type ofnon-static class member functions.