forked from boostorg/fusion
- Construct from elements is enabled iff each argument is_convertible to corresponding element. - Construct from sequence is enabled iff the single argument is a fusion sequence. - C++11 vector and tuple also disable construct from sequence that are shorter than the destination. C++03 gives incorrect is_convertible responses in this situation and fails to compile if that constructor is used; C++11 can have instantation errors in and_<is_convertible<U, T>...> without the additional check. - C++11 tuple and vector support truncation conversion and assignment like all other sequences.