[Boost-build] Jamfile syntax question

Subject: [Boost-build] Jamfile syntax question
From: Robert Ramey (ramey_at_[hidden])
Date: 2016-12-23 12:03:27

My jam file includes the following

# these are used to shorten testing while in development.  It permits
# testing to be applied to just a particular type of archive
if ! $(BOOST_ARCHIVE_LIST) {
     BOOST_ARCHIVE_LIST =
         "text_archive.hpp"
         "text_warchive.hpp"
         "binary_archive.hpp"
         "xml_archive.hpp"
         "xml_warchive.hpp"
     ;
     # enable the tests which don't depend on a particular archive
     BOOST_SERIALIZATION_TEST = true ;
}

in order to define a list of archive types to test.  I would like to 
alter this so that it does not include the warchive versions if the 
target plaform doesn't support wstream_buf.  I'm unclear as to how that 
should be implemented.  My first idea would be to use something like this:

if ! $(BOOST_ARCHIVE_LIST) {
     if [ requires std_wstreambuf ] {
         BOOST_ARCHIVE_LIST =
             "text_archive.hpp"
             "text_warchive.hpp"
             "binary_archive.hpp"
             "xml_archive.hpp"
             "xml_warchive.hpp"
         ;
     }
     else {
         BOOST_ARCHIVE_LIST =
             "text_archive.hpp"
             "binary_archive.hpp"
             "xml_archive.hpp"
         ;
     }

     # enable the tests which don't depend on a particular archive
     BOOST_SERIALIZATION_TEST = true ;
}

Will this work as want it to?

Robert Ramey