[cfe-dev] [llvm-dev] problem (and fix) with -fms-extensions

[Marc Espie via cfe-dev]

On Wed, May 17, 2017 at 03:55:06PM -0700, Reid Kleckner wrote:
> 
>    On Wed, May 17, 2017 at 3:22 PM, Marc Espie <[1]espie at nerim.net> wrote:
> 
>      On Wed, May 17, 2017 at 01:01:07PM -0700, Reid Kleckner wrote:
>      >
>      >Â  Â  I'd rather not add new pre-defined macros if we can avoid it.
>      There are
>      >Â  Â  already too many. You can probably detect this situation
>      with:
>      >Â  Â  #if defined(_MSC_EXTENSIONS) && !defined(_WCHAR_T_DEFINED)
>      >
>      Was this added recently ?
>      There is no _MSC_EXTENSIONS in the clang I'm using...
> 
>    Looks like we only define it for Windows targets.
>    How about __is_identifier?
>    $ cat t.cpp
>    #if !__is_identifier(__wchar_t)
>    #error "have __wchar_t"
>    #else
>    #error "no __wchar_t"
>    #endif

Nope, that will trigger errors on non clang compilers.

Why do you fight so hard against a simple solution ?