BOOST_VMD_IS_LIST — Determines if a sequence is a Boost pplib list.
// In header: <boost/vmd/is_list.hpp> BOOST_VMD_IS_LIST(sequence)
The macro checks that the sequence is a pplib list. It returns 1 if it is a list, else if returns 0.
sequence = input as a possible Boost PP list.
returns = 1 if it a list, else returns 0.
The macro will generate a preprocessing error if the input is in the form of a list but its end-of-list marker, instead of being an identifier, is a preprocessor token which VMD cannot parse, as in the example '(anything,&BOOST_PP_NIL)' which is a valid tuple but an invalid list.