BOOST_VMD_TUPLE_PUSH_FRONT — inserts an element at the beginning of a tuple.
// In header: <boost/vmd/tuple/push_front.hpp> BOOST_VMD_TUPLE_PUSH_FRONT(tuple, elem)
tuple = tuple to insert an element at. elem = element to insert.
If the tuple is an empty tuple the result is a tuple with the single element. Otherwise the result is a tuple after inserting the element at the beginning.
