Self-inlining anonymous closures in C++
matt.might.net
matt.might.net
http://www.boost.org/doc/libs/1_44_0/libs/spirit/phoenix/doc...
It's just a tutorial on how such things are done. :)
The reality is that that kind of technique allows to produce extremely fast code because the compiler has got so much "certain" information at compile time that it can optimize very aggressively.
It's more powerful than vanilla C macros because it works with the compiler, not the pre-processor.
YMMV whether that's a blessing or a curse, though!