https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121702
--- Comment #6 from shyeyian <shyeyian at petalmail dot com> --- (Append to previous comment ^) a::f() is visiable in c.cpp (because b export imports a), b::f() is invisiable in c.cpp when using g++, is visiable in c.cpp when using clang++. (Note: a::f() should be constexpr int f() for later static_assert, ignore this tiny mistake) **Thank you!!**
