...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::unary_plus — A metafunction for generating unary plus expression types,
a grammar element for matching unary plus expressions, and
a PrimitiveTransform that dispatches to the
proto::pass_through<>
transform.
// In header: <boost/proto/traits.hpp> template<typename T> struct unary_plus : proto::transform< unary_plus<T> > { // types typedef proto::expr< proto::tag::unary_plus, proto::list1< T > > type; typedef proto::basic_expr< proto::tag::unary_plus, proto::list1< T > > proto_grammar; // member classes/structs/unions template<typename Expr, typename State, typename Data> struct impl : proto::pass_through<unary_plus>::template impl<Expr, State, Data> { }; };