Re: [boost] [config] Configuring for C++14 and later library features.

Subject: Re: [boost] [config] Configuring for C++14 and later library features.
From: Agustín K-ballo Bergé (kaballo86_at_[hidden])
Date: 2015-04-24 09:33:05

On 4/24/2015 9:32 AM, John Maddock wrote:
> Folks,
>
> I have an open PR for adding BOOST_NO_CXX14_INTEGER_SEQUENCE
> (https://github.com/boostorg/config/pull/58).
>
> Unfortunately, the correct way to check for std::integer_sequence is to
> include <utility> and then check for __cpp_lib_integer_sequence.

I wouldn't call that the "correct way", it is just **a** way. In 
particular, it is a "safe way", as in that false negatives are perfectly 
acceptable (and IIRC neither libc++ nor msvc provide these yet).

> This doesn't look acceptable to me, but what to do?

I suggest to do what has always been done so far (craft tests, detect 
stdlib, set macros explicitly). Is there a reason that I'm missing as 
for which the traditional approach doesn't fit here?

The feature tests from SD-6 are for convenience, there's no point in 
using them if doing so would be inconvenient.

Regards,
-- 
Agustín K-ballo Bergé.-
http://talesofcpp.fusionfenix.com