...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::proto::comma — A metafunction for generating comma expression types,
a grammar element for matching comma expressions, and
a PrimitiveTransform that dispatches to the
proto::pass_through<>
transform.
// In header: <boost/proto/traits.hpp> template<typename T, typename U> struct comma : proto::transform< comma<T, U> > { // types typedef proto::expr< proto::tag::comma, proto::list2< T, U > > type; typedef proto::basic_expr< proto::tag::comma, proto::list2< T, U > > proto_grammar; // member classes/structs/unions template<typename Expr, typename State, typename Data> struct impl : proto::pass_through<comma>::template impl<Expr, State, Data> { }; };