[patch] libstdc++/65473 Make <ciso646> define libstdc++ version macros.

[Jonathan Wakely]

On 03/09/15 13:22 -0600, Martin Sebor wrote:
>On 09/03/2015 04:58 AM, Jonathan Wakely wrote:
>>This change would allow including <ciso646> to be used to check for
>>__GLIBCXX__ and detect whether youre using libstdc++ or not. Howard
>>Hinnant recommends including that header for libc++ because it has no
>>other effects in C++.
>>
>>We could make every <cxxx> header include <bits/c++config.h> so that
>>any of them can be used, but I can't be bothered doing that change!
>>This makes it work for the one header that is recommended to be used,
>>but of course that doesn't help people using older versions of
>>libstdc++, who still need to include some other header.
>>
>>Is this worth doing?
>
>I'd say it's worth doing consistently, in every header.

OK, I'll add it to the others as well.