Re: [boost] [C++0x] More config macros needed

Subject: Re: [boost] [C++0x] More config macros needed
From: John Maddock (john_at_[hidden])
Date: 2009-05-13 04:48:19

> GCC 4.3 and even more so 4.4 have implemented significant portions of
> the C++0x core language, and provide lots of C++0x standard library
> components too.
>
> Microsoft 2010 beta 1 will ship "real soon", and it too will have some
> major C++0x core language features, and also some C++0x standard
> library components.
>
> Thus we need more config macros, particularly those aimed at the
> standard library. A possible approach:
>
> BOOST_NO_CONCEPTS     // needed to tell if headers have been conceptized
>
> BOOST_NO_*_HDR             // for each new C++0x header; * is name of 
> header
>
> For example, BOOST_NO_CHRONO_HDR is defined unless header <chrono> is 
> present.
>
> I'm proposing we not try to identify whether or no the header is
> complete. If BOOST_NO_CONCEPTS is defined, the header obviously hasn't
> been conceptized. Ditto anything else that depends on any other new
> core language feature that hasn't been implemented. Other incomplete
> aspects will have to be dealt with by testing the library version. We
> don't want feature macros to proliferate unduly; they are more work to
> create and maintain than you might think, and if there are a lot of
> them it gets very confusing.

Sounds reasonable to me, especially if someone other than me gets to do them 
:-)

John.