As promised, I have some results. My work can be found this time at <http://groups.yahoo.com/group/boost/files/pp_math.zip>. The example program is simpler and has been confirmed to work correctly when compiled under MinGW 3.2 and MSVC 7.1 (using the VC 2003 Toolkit). Later on I'll test it using MSVC 6. The usual caveats that apply to other macros (no incrementing, decrementing, or runtime functions with side effects can be called from within parameters) apply here. Once again, comments welcome! Cromwell Enage __________________________________ Do you Yahoo!? SBC Yahoo! - Internet access at a great low price. http://promo.yahoo.com/sbc/