boost::proto::greater_equal — 一个用于生成大于等于表达式类型的元函数,一个用于匹配大于等于表达式的语法元素,以及一个 PrimitiveTransform,它分派到 proto::pass_through<>
转换。
// In header: <boost/proto/traits.hpp> template<typename T, typename U> struct greater_equal : proto::transform< greater_equal<T, U> > { // types typedef proto::expr< proto::tag::greater_equal, proto::list2< T, U > > type; typedef proto::basic_expr< proto::tag::greater_equal, proto::list2< T, U > > proto_grammar; // member classes/structs/unions template<typename Expr, typename State, typename Data> struct impl : proto::pass_through<greater_equal>::template impl<Expr, State, Data> { }; };