Make __has_include portable in C

Question

__has_include is included in the C++ standard since C++17. However, in C, is just supported by compilers that implement it as an extension. As far as I am aware, just GCC and clang support it. Is there a way I can accomplish a similar effect portably in C? MSVC just seems to support it for C++.

Answer 1

__has_include was added to C23; see here.