Re: [Boost-build] May I use conditions with define?

Subject: Re: [Boost-build] May I use conditions with define?
From: Gevorg Voskanyan (v_gevorg_at_[hidden])
Date: 2011-04-07 12:44:04

Dmitry Timoshenko wrote:
> Hello,
> 
> may I write something like this in requrements section of the  project (or lib  
>rule)?
> 
> <define>UNICOMM_USE_COMPLEX_XML:<library>/smart//smart_data
> 
> if  user passes to bjam define=UNICOMM_USE_COMPLEX_XML
> 
> I tried, but it  doesn't matter... or may be it is possible to achive goal by 
>another  way?
> 
> Thank  you.

Hello Dmitry,

As 'define' is a free feature, it is not possible the way you wrote it AFAIK. 
You can try this however:

replace <define>UNICOMM_USE_COMPLEX_XML:<library>/smart//smart_data
with <conditional>@use-complex-xml-properties

where use-complex-xml-properties is defined as:
rule use-complex-xml-properties ( properties * )
{
   if <define>UNICOMM_USE_COMPLEX_XML in $(properties) {
       return <library>/smart//smart_data ;
   }
}

Or, another approach would be:

import feature ;
feature.feature use-complex-xml : off on : propagated optional composite ;
feature.compose <use-complex-xml>on : 
<library>/smart//smart_data <define>UNICOMM_USE_COMPLEX_XML ;

then,
bjam use-complex-xml=on

HTH,
Gevorg