Re: [boost] [config] defining __has_extension in suffix.hpp?

Subject: Re: [boost] [config] defining __has_extension in suffix.hpp?
From: John Maddock (boost.regex_at_[hidden])
Date: 2015-01-22 03:56:12

> It's useful to have
>
> #ifndef __has_feature
> #define __has_feature(x) 0
> #endif
>
> #ifndef __has_extension
> #define __has_extension __has_feature
> #endif
>
> in suffix.hpp so that one can then use __has_extension(foo) everywhere
> without fear. Otherwise, even
>
> #if defined(__clang__) && defined(__has_extension) && __has_extension(foo)
>
> is a preprocessor error when __has_extension is not defined (which it
> isn't when not on Clang.)

Good point.

However, aren't those reserved symbols?  If we're being pedantic.... John.