Re: [boost] [config] Standard version macros proposal -- Reviving the compiler version macros.

From: John Maddock (john_at_[hidden])
Date: 2005-10-17 04:37:54

> After reading up on past discussions about what people want from a set
> of standard macros for compiler identification, I put together a wiki
> page with past information on the subject and my ideas as to what the
> consensus is. And basic proposal based on the ideas:
>
> http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?BoostConfig
>
> Discussion, contributions, funny anecdotes are welcome :-)

>(1) BOOST_VERSION_NUMBER macro

Overall, I like it, as someone else suggested you may need to reserve a few 
more digits here and there, as long as we don't end up overflowing a 32-bit 
int of course.

> For each compiler 'boost/config/select_compiler_config.hpp' would define a 
> macro as '0' by default

That won't work: users can short circuit that header so that it doesn't get 
included as documented here: 
http://www.boost.org/libs/config/config.htm#advanced_config

We could define any macro that's not already been defined in suffix.hpp 
though.

I like your choice of names for the macros BTW.

> For some compiler toolsets it's possible that multiple macros are defined. 
> For instance this would be the case for EDG based compilers >where one 
> would want to know both the EDG version and the specific vnedor compiler 
> version. ANother being compilers that are >frontends to other system 
> compilers, like the Intel compiler. For those reasons it would be better 
> to create new headers which contain the >above definitions per compiler. 
> This would allow them to be defined once and included where appropriate. 
> Hence we would need to add >the following headers:

I don't understand the logic there, why the extra headers?

Taking Intel on Linux as an example, it includes common_edg.hpp which would 
define BOOST_CXX_EDG, then intel.hpp would define BOOST_CXX_INTEL, I'm not 
sure whether BOOST_CXX_GCC should be defined as well, but intel.hpp could 
define it if required.

Likewise with the platform headers: I don't see the need for the extra 
headers, the only macro that can be defined in combination with the other 
appears to be BOOST_PLATFORM_POSIX and presumably that would be defined in 
the existing posix_features.hpp?

Looks like you need to cull some more std lib information to get the version 
numbers :-)

John.