[Bug c/91937] _Generic Feature Expansion

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91937

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Then perhaps you want to use C++ instead of C?
The way the preprocessor works and the way _Generic works is defined in the C
standard, we can't handle it just differently from what the standard says, and
the type decisions for _Generic can't be done during preprocessing, because
that requires syntactic analysis of the source.
E.g. glibc tgmath.h implementation using _Generic was suffering similarly and
lead into the introduction of compiler builtin that handles what tgmath.h
needs.