Re: [boost] [predef] Announce: Build time configuration forPredefdefs.

Subject: Re: [boost] [predef] Announce: Build time configuration forPredefdefs.
From: Peter Dimov (lists_at_[hidden])
Date: 2015-01-28 06:26:51

> Regarding predef-require, is it possible to combine several conditions 
> using and/or? I see that you've said
>
> > You can specify multiple checked expressions that are all required.
>
> which probably means "and" (predef-require probably returns <build>no when 
> the condition doesn't hold, so I see how it can be repeated).

Looking at the code, I see that what you meant was

[ predef-require "BOOST_COMP_MSVC <= 15.0.0 BOOST_COMP_MSVC >= 12.0.0" ]

that is, multiple expressions can be specified in the string itself, and all 
of them need to hold.

Not, as I thought,

[ predef-require "BOOST_COMP_MSVC <= 15.0.0" ] [ predef-require 
BOOST_COMP_MSVC >= 12.0.0" ]

although this should also work, I think.

But there seems to be no way to specify logical or. Although it could 
probably be done by duplicating the run rule.

run msvc-or-gcc-test.cpp : : : [ predef-require "BOOST_COMP_MSVC" ] ;
run msvc-or-gcc-test.cpp : : : [ predef-require "BOOST_COMP_GCC" ] ;

If you're taking (feature &~ pull) requests, I would venture that it would 
be more intuitive if it supported

[ predef-require "BOOST_COMP_MSVC <= 15.0.0 && BOOST_COMP_MSVC >= 12.0.0" ]

and

[ predef-require "BOOST_COMP_MSVC || BOOST_COMP_GCC" ]

though :-)