Hello all, I am trying to start learning the Boost MPL. The internals are more interesting for me then the usage I read both Abrahams&Gurtovoy and Alexandrescu books (both excelent btw) Some things i still don't quite understand: 1. How (or rather Why) does is_class works. 2. Same for is_enum 3. Can someone explain how MPL lambda works specially how the "_" works I tried to scan some of the archives but could not find any definite answer - i guess the discussions if they were are lost. P.S. neat trick to someone who try to learn the internals is to make a program that just include the header u interested to learn and just do the "pre-compile" stage (/EP /P flags in VC7.1 iirc) - you get a nice header without the unreadable MACROS. Thanks