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