Errors when trying to use C++ modules with cmake and GCC

[Jonathan Wakely]

On Wed, 8 Feb 2023 at 12:14, HHN wrote:
>
> I apologise for not providing the complete context, after compiling I had tried to build the test suite and faced errors. I have attached the logs of this failure. ninja fails with
> ninja: build stopped: subcommand failed.
>
> No such issues had occurred with g++-11. Only changes made to was changing the compiler in CMake

error: ‘intmax_t’ is not a member of ‘std’; did you mean ‘intmax_t’?

This is clearly a bug in the software. If you want to use
std::intmax_t you need to include <cstdint> not <stdint.h>. If you
want to include <stdint.h> then you need to use ::intmax_t not
std::intmax_t.

The C++ library headers are cleaner than in previous releases and so
buggy code that used to compile is now rejected.
https://gcc.gnu.org/gcc-13/porting_to.html#header-dep-changes