g++ 12 -std=gnu++20

[Corinna Vinschen]

On Oct 30 09:06, Brian Inglis via Cygwin wrote:
> Hi folks,
> 
> Trying to update a package using c++ (requires gcc 12.4+ for adequate c++
> 2020 support) and getting confusing error messages.
> 
> It appears that noexcept in the header files may here redefined by the
> compiler or headers as __GLIBC_NOEXCEPT.

There's one underscore too many, that should be _GLIBCXX_NOEXCEPT.

> Those errors look to me like a failure to detect that *glibc* is not available.
> Or is *GLIBCXX* actually *glib* for *cxx*, so this could be a library or
> compiler issue?

It's used in the gcc c++ headers, defined in c++config.h and part of the
gcc-g++ package.  The packaging on Fedora puts this file into the
libstdc++-devel package, which is more helpful, I guess.


Corinna