Two small issues with the (excellent!) Tuple library:
0) Comparison of tuples with operator!= is broken. The fix is easy enough - it only requires a change of the return value in the specialization of neq - template<> inline bool neq<null_type,null_type>(const null_type&, const null_type&) - to return false (or !true for the one-character-fix :-)).
1) length is not documented. Shouldn't it be? It can be important for some generic constructs.
Regards,
Bjorn Karlsson