Re: [boost] [type_traits] Rewrite and dependency free version

Subject: Re: [boost] [type_traits] Rewrite and dependency free version
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2015-01-16 04:53:55

On Friday 16 January 2015 09:46:42 John Maddock wrote:
> > While looking at this, I also noticed that
> > BOOST_NO_CXX11_HDR_TYPE_TRAITS is set for g++ and clang, even though
> > they do have <type_traits>. The config test fails because they don't
> > have is_trivially_* and aligned_union. Fair enough, but the rest of the
> > traits are there and usable, so I'm not entirely sure about this.
> 
> Me neither.  Basically no one's complained so I've left it set.  <shrug>
> I guess.  Could go either way on that.   John.

AFAIR, by convention we set HDR macros when the header is fully usable. I 
think that's fair. We could introduce other sub-feature macros for finer 
grained checks, like BOOST_NO_CXX11_TYPE_INSPECTION_TRAITS, 
BOOST_NO_CXX11_TYPE_TRANSFORM_TRAITS, etc.