This extra line doesn't seem to be in CVS yet, did you forget to commit, or should I add it for you? :-)
Apologies: I should have been clearer: bcp has been updated to recognise //@bcp optional message-text #include <optional-header.hpp> But I deliberately haven't changed any headers, please do go ahead and experiment with this and make changes to whatever headers you see fit to :-) There have also been some useful suggestions from Jeff Garland that I want to mull over, conceptually we could have some thing like: //@bcp default=enable name=Wow Optional feature Wow is enabled by default use --disable-Wow to suppress it's inclusion or: //@bcp default=disable name=Wow Optional feature Wow is disabled by default use --enable-Wow to force it's inclusion and //@bcp suppress which would unconditionally suppress the inclusion of the following include. But I haven't really thought all that through yet. Jeff's idea of a separate file for optional includes would make it easier for lib authors to exclude inclusion of headers through a whole set of files, but requires rather more modifications to bcp than may be wise this close to a release? There may be synergies with Boost.Build as well, as I believe that scans headers in a similar way to bcp. John.