[Bug c++/120990] Narrowing conversion in std::function return value is not reported

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120990

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Clang suppresses warnings inside C++ standard library header, MSVC doesn't.