Re: Reducing duplication of bit operation code.

[Collin Funk]

Hi Bruno,

Bruno Haible <bruno@clisp.org> writes:

> Also, I see that MSVC is not well covered by this default in stdbit.in.h:
>
> #else
> /* This platform is so old that it lacks typeof, so _Generic is likely
>    missing or unreliable.  The C23 standard seems to allow yielding B
>    (which is always unsigned long long int), so do that.  */
> # define _GL_STDBIT_TYPEOF_CAST(a, b) (b)
> #endif
>
> Can it be improved?

Good point.

I see that MSVC supports both typeof and __typeof__ since Visual Studio
17.9. The difference is 'typeof' requires compiling with the latest
language standard, but '__typeof__' can be used with any language
version [1].

I've applied the two attached patches to detect them in stdbit-h and
intprops using the _MSC_VER [2].

Collin

[1] https://learn.microsoft.com/en-us/cpp/c-language/typeof-c?view=msvc-170
[2] 
https://learn.microsoft.com/en-us/cpp/overview/compiler-versions?view=msvc-170#version-macros

0001-stdbit-h-Detect-MSVC-__typeof__-support.patch
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0002-intprops-Detect-MSVC-__typeof__-support.patch
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