/*============================================================================= Copyright (c) 2014 Joel de Guzman Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) =============================================================================*/ #ifndef BOOST_SPIRIT_X3_DIRECTIVE_WITH_HPP #define BOOST_SPIRIT_X3_DIRECTIVE_WITH_HPP #include <boost/spirit/home/x3/support/unused.hpp> #include <boost/spirit/home/x3/core/parser.hpp> namespace boost { namespace spirit { namespace x3 { /////////////////////////////////////////////////////////////////////////// // with directive injects a value into the context prior to parsing. /////////////////////////////////////////////////////////////////////////// template <typename Subject, typename Derived, typename T> struct with_value_holder : unary_parser<Subject, Derived> { typedef unary_parser<Subject, Derived> base_type; mutable T val; constexpr with_value_holder(Subject const& subject, T&& val) : base_type(subject) , val(std::forward<T>(val)) {} }; template <typename Subject, typename Derived, typename T> struct with_value_holder<Subject, Derived, T&> : unary_parser<Subject, Derived> { typedef unary_parser<Subject, Derived> base_type; T& val; constexpr with_value_holder(Subject const& subject, T& val) : base_type(subject) , val(val) {} }; template <typename Subject, typename ID, typename T> struct with_directive : with_value_holder<Subject, with_directive<Subject, ID, T>, T> { typedef with_value_holder<Subject, with_directive<Subject, ID, T>, T> base_type; static bool const is_pass_through_unary = true; static bool const handles_container = Subject::handles_container; typedef Subject subject_type; constexpr with_directive(Subject const& subject, T&& val) : base_type(subject, std::forward<T>(val)) {} template <typename Iterator, typename Context , typename RContext, typename Attribute> bool parse(Iterator& first, Iterator const& last , Context const& context, RContext& rcontext, Attribute& attr) const { return this->subject.parse( first, last , make_context<ID>(this->val, context) , rcontext , attr); } }; template <typename ID, typename T> struct with_gen { T&& val; template <typename Subject> constexpr with_directive<typename extension::as_parser<Subject>::value_type, ID, T> operator[](Subject const& subject) const { return { as_parser(subject), std::forward<T>(val) }; } }; template <typename ID, typename T> constexpr with_gen<ID, T> with(T&& val) { return { std::forward<T>(val) }; } }}} #endif