I propose to add promote, integral_promotion and floating_point_promotion class templates to type_traits library. You can download it from http://cpp-experiment.sourceforge.net/promote-20050917.tar.gz or browse it online http://cpp-experiment.sourceforge.net/promote-20050917/ I've tried it on different compilers with various success: GNU/Linux (gentoo-hardened): gcc 3.3 and 3.4, Intel 7, 8 and 9 Windows: VC7 free compiler Sparc Solaris: Sun C++ 5.3 and 5.7 See comments at the beginning of promote_enum_test.cpp for what is broken. http://cpp-experiment.sourceforge.net/promote-20050917/libs/type_traits/test... I used to compile tests on VC6 and I'm pretty sure I can add workarounds if someone is still interested. Actually, it compiled the tests better then VC7. As for Borland 5.5, is_enum is broken and I don't see any reason to support this compiler. -- Alexander