| // Copyright (c) 2001-2011 Hartmut Kaiser | |
| // | |
| // 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) | |
| #if !defined(BOOST_SPIRIT_SUPPORT_META_CREATE_NOV_21_2009_0327PM) | |
| #define BOOST_SPIRIT_SUPPORT_META_CREATE_NOV_21_2009_0327PM | |
| #if defined(_MSC_VER) | |
| #pragma once | |
| #endif | |
| #include <boost/spirit/home/support/unused.hpp> | |
| #include <boost/version.hpp> | |
| #include <boost/proto/proto.hpp> | |
| #include <boost/utility/result_of.hpp> | |
| #include <boost/type_traits/add_const.hpp> | |
| #include <boost/type_traits/add_reference.hpp> | |
| #include <boost/type_traits/remove_const.hpp> | |
| #include <boost/type_traits/remove_reference.hpp> | |
| #include <boost/fusion/include/fold.hpp> | |
| #include <boost/mpl/and.hpp> | |
| #include <boost/mpl/not.hpp> | |
| // needed for workaround below | |
| #if defined(__GNUC__) && ((__GNUC__ < 4) || (__GNUC__ == 4) && (__GNUC_MINOR__ < 3)) | |
| #include <boost/type_traits/is_same.hpp> | |
| #endif | |
| namespace boost { namespace spirit { namespace traits | |
| { | |
| /////////////////////////////////////////////////////////////////////////// | |
| // This is the main dispatch point for meta_create to the correct domain | |
| template <typename Domain, typename T, typename Enable = void> | |
| struct meta_create; | |
| /////////////////////////////////////////////////////////////////////////// | |
| // This allows to query whether a valid mapping exists for the given data | |
| // type to a component in the given domain | |
| template <typename Domain, typename T, typename Enable = void> | |
| struct meta_create_exists : mpl::false_ {}; | |
| }}} | |
| namespace boost { namespace spirit | |
| { | |
| /////////////////////////////////////////////////////////////////////////// | |
| namespace detail | |
| { | |
| template <typename T> | |
| struct add_const_ref | |
| : add_reference<typename add_const<T>::type> {}; | |
| template <typename T> | |
| struct remove_const_ref | |
| : remove_const<typename remove_reference<T>::type> {}; | |
| // starting with Boost V1.42 fusion::fold has been changed to be compatible | |
| // with mpl::fold (the sequence of template parameters for the meta-function | |
| // object has been changed) | |
| #if BOOST_VERSION < 104200 | |
| /////////////////////////////////////////////////////////////////////// | |
| template <typename OpTag, typename Domain> | |
| struct nary_proto_expr_function | |
| { | |
| template <typename T> | |
| struct result; | |
| // this is a workaround for older versions of g++ (< V4.3) which apparently have | |
| // problems with the following template specialization | |
| #if defined(__GNUC__) && ((__GNUC__ < 4) || (__GNUC__ == 4) && (__GNUC_MINOR__ < 3)) | |
| template <typename F, typename T1, typename T2> | |
| struct result<F(T1, T2)> | |
| { | |
| BOOST_STATIC_ASSERT((is_same<F, nary_proto_expr_function>::value)); | |
| #else | |
| template <typename T1, typename T2> | |
| struct result<nary_proto_expr_function(T1, T2)> | |
| { | |
| #endif | |
| typedef typename remove_const_ref<T2>::type left_type; | |
| typedef typename | |
| spirit::traits::meta_create<Domain, T1>::type | |
| right_type; | |
| typedef typename mpl::eval_if< | |
| traits::not_is_unused<left_type> | |
| , proto::result_of::make_expr<OpTag, left_type, right_type> | |
| , mpl::identity<right_type> | |
| >::type type; | |
| }; | |
| template <typename T> | |
| typename result<nary_proto_expr_function(T, unused_type const&)>::type | |
| operator()(T, unused_type const&) const | |
| { | |
| typedef spirit::traits::meta_create<Domain, T> right_type; | |
| return right_type::call(); | |
| } | |
| template <typename T1, typename T2> | |
| typename result<nary_proto_expr_function(T1, T2)>::type | |
| operator()(T1, T2 const& t2) const | |
| { | |
| // we variants to the alternative operator | |
| typedef spirit::traits::meta_create<Domain, T1> right_type; | |
| return proto::make_expr<OpTag>(t2, right_type::call()); | |
| } | |
| }; | |
| #else | |
| /////////////////////////////////////////////////////////////////////// | |
| template <typename OpTag, typename Domain> | |
| struct nary_proto_expr_function | |
| { | |
| template <typename T> | |
| struct result; | |
| // this is a workaround for older versions of g++ (< V4.3) which apparently have | |
| // problems with the following template specialization | |
| #if defined(__GNUC__) && ((__GNUC__ < 4) || (__GNUC__ == 4) && (__GNUC_MINOR__ < 3)) | |
| template <typename F, typename T1, typename T2> | |
| struct result<F(T1, T2)> | |
| { | |
| BOOST_STATIC_ASSERT((is_same<F, nary_proto_expr_function>::value)); | |
| #else | |
| template <typename T1, typename T2> | |
| struct result<nary_proto_expr_function(T1, T2)> | |
| { | |
| #endif | |
| typedef typename remove_const_ref<T1>::type left_type; | |
| typedef typename | |
| spirit::traits::meta_create<Domain, T2>::type | |
| right_type; | |
| typedef typename mpl::eval_if< | |
| traits::not_is_unused<left_type> | |
| , proto::result_of::make_expr<OpTag, left_type, right_type> | |
| , mpl::identity<right_type> | |
| >::type type; | |
| }; | |
| template <typename T> | |
| typename result<nary_proto_expr_function(unused_type const&, T)>::type | |
| operator()(unused_type const&, T) const | |
| { | |
| typedef spirit::traits::meta_create<Domain, T> right_type; | |
| return right_type::call(); | |
| } | |
| template <typename T1, typename T2> | |
| typename result<nary_proto_expr_function(T1, T2)>::type | |
| operator()(T1 const& t1, T2) const | |
| { | |
| // we variants to the alternative operator | |
| typedef spirit::traits::meta_create<Domain, T2> right_type; | |
| return proto::make_expr<OpTag>(t1, right_type::call()); | |
| } | |
| }; | |
| #endif | |
| } | |
| /////////////////////////////////////////////////////////////////////// | |
| template <typename T, typename OpTag, typename Domain> | |
| struct make_unary_proto_expr | |
| { | |
| typedef spirit::traits::meta_create<Domain, T> subject_type; | |
| typedef typename proto::result_of::make_expr< | |
| OpTag, typename subject_type::type | |
| >::type type; | |
| static type call() | |
| { | |
| return proto::make_expr<OpTag>(subject_type::call()); | |
| } | |
| }; | |
| /////////////////////////////////////////////////////////////////////////// | |
| template <typename Sequence, typename OpTag, typename Domain> | |
| struct make_nary_proto_expr | |
| { | |
| typedef detail::nary_proto_expr_function<OpTag, Domain> | |
| make_proto_expr; | |
| typedef typename fusion::result_of::fold< | |
| Sequence, unused_type, make_proto_expr | |
| >::type type; | |
| static type call() | |
| { | |
| return fusion::fold(Sequence(), unused, make_proto_expr()); | |
| } | |
| }; | |
| /////////////////////////////////////////////////////////////////////////// | |
| namespace detail | |
| { | |
| // Starting with newer versions of Proto, all Proto expressions are at | |
| // the same time Fusion sequences. This is the correct behavior, but | |
| // we need to distinguish between Fusion sequences and Proto | |
| // expressions. This meta-function does exactly that. | |
| template <typename T> | |
| struct is_fusion_sequence_but_not_proto_expr | |
| : mpl::and_< | |
| fusion::traits::is_sequence<T> | |
| , mpl::not_<proto::is_expr<T> > > | |
| {}; | |
| } | |
| }} | |
| #endif |