Re: [boost] [config] Using SD-6 macros

Subject: Re: [boost] [config] Using SD-6 macros
From: Edward Diener (eldiener_at_[hidden])
Date: 2015-06-12 22:26:49

On 6/12/2015 1:05 PM, Peter Dimov wrote:
> Edward Diener wrote:
>
>> About what std lib features are you speaking ? Most of the things I
>> see at
>> https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations
>> are predefined.
>
> All __cpp_lib macros have an associated header, although I don't know if
> we currently have Boost.Config equivalents for any of them.

I can see them but they are all C++14 features. Are we really objecting 
to including a particular standard library header in order to test for 
the existence of the equivalent SD-6 macro ? If so I think we are dead 
wrong to raise that objection unless we have an absolutely sure way of 
knowing for the particular compiler implementation outside of SD-6.

>
> It seems to me that there's no macro for SD-6 itself though. When
> __cpp_something is not defined, you don't know whether this is because
> 'something' is not implemented or because SD-6 is not implemented.

What difference could it possibly make ? You test if a macro is defined 
and if it is not you try something else. If it is you have your answer.