[Boost-users] [Fusion] value_at_c and its relatives not applicable to Associative Sequence?

Hi, the document says that 'value_at_c' accepts a Forward Sequence, and set/map, which is of Associative Sequence as well as Forward Sequence, why the following does not work? #include #include int main() { namespace fs = boost::fusion; typedef fs::result_of::value_at_c >::type type; return 0; }