Following on the concept by Peter Dimov of using the BBv2 config feature combined with tests I'm pleased to announce that Predef now has a similar feature. In the develop branch of Predef you can now do the following: import ../libs/predef/check/predef : require : predef-require ; run macos_only_test.cpp : : : [ predef-require "BOOST_OS_MACOS" ] ; run vc15_only_test.cpp : : : [ predef-require "BOOST_COMP_MSVC >= 15.0.0" ] ; The expression(s) to check can use any of the definitions that Predef has. The general for is: "<DEF> <OP> <VERSION>". Where <OP> is any of the usual C/C++ relational operators. And <VERSION> is a partial or complete triplet of integers. You can specify multiple checked expressions that are all required. Also part of this is a more general "check" rule that allows for custom build requirements. For example: import ../libs/predef/check/predef : require check : predef-require predef-check ; run macos_only_test.cpp : : : [ predef-require "BOOST_OS_MACOS" ] ; run vc15_only_test.cpp : : : [ predef-check "BOOST_COMP_MSVC >= 15.0.0" : <define>THIS_IS_MSVC : <build>no ] ; I'll put this into master as soon as I have appropriate documentation. Enjoy. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail