Re: [Boost-build] Subproperty valiidity

From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2019-07-27 14:05:56

AMDG

On 7/27/19 7:18 AM, Edward Diener via Boost-build wrote:
> In the Boost Build manual it states in section 5.8.2:
> 
> "Subproperty validity may be restricted so that certain values are valid
> only in the presence of certain other subproperties. For example, it is
> possible to specify that the <gcc-target>mingw property is only valid in
> the presence of <gcc-version>2.95.2."
> 
> However it does not explain how to specify, or enforce, such subproperty
> validity. How can this be done in Boost Build ?
> 
> As a practical example if I have:
> 
> feature.subfeature toolset gcc : std : c03 c11 c14 c17 : optional
> composite propagated ;
> 

If it works, which I'm somewhat doubtful about, as I was
unaware this this was possible, the syntax would be:

feature.subfeature toolset gcc-8.3 : ... ;

> feature.compose <toolset-gcc:std>c03 : <cxxflags>-std=c++03 ;
> feature.compose <toolset-gcc:std>c11 : <cxxflags>-std=c++11 ;
> feature.compose <toolset-gcc:std>c14 : <cxxflags>-std=c++14 ;
> feature.compose <toolset-gcc:std>c17 : <cxxflags>-std=c++1z ;
> 
> I might want to allow:
> 
> b2 toolset=gcc-8.3-c17
> 
> but I might not want to allow:
> 
> b2 toolset=gcc-4.8-c17
> 
> Is there a way of enforcing this by some jam code in my user-configf.jam
> file ?
> 

In Christ,
Steven Watanabe