Re: [boost] New C++14 config macros - opinions wanted

Subject: Re: [boost] New C++14 config macros - opinions wanted
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2014-09-25 03:03:27

On Thu, Sep 25, 2014 at 10:50 AM, Stephen Kelly <hello_at_[hidden]> wrote:
> John Maddock wrote:
>
>> There is a pull request to add new config macros for C++14 features
>> (https://github.com/boostorg/config/pull/39), I have a few questions
>> really, particularly for those more familiar with C++14 than me:
>>
>> * Do we need these?
>
> As a data-point, Qt expects the SD-6 macros to be present and working for
> C++14 features, instead of providing similar macros.

The problem with SD-6 is that different compilers may implement
features with different levels of conformance, including SD-6 itself.
IMHO, besides __has_include, these feature test macros are not very
useful and are basically equivalent to testing the compiler version
and similar macros.

I don't think Boost libraries should rely on these macros directly.
Boost.Config, OTOH, may use these macros to define its own macros, if
it is known that the particular compiler supports SD-6 correctly
enough. We can use these macros as reference for naming decisions as
well (although I like MEMBER_INITIALIZERS_AND_AGGREGATES more than the
cryptic aggregate_nsdmi).