1 /////////////////////////////////////////////////////////////////////////////// 2 /// \file reverse.hpp 3 /// Proto callables Fusion reverse 4 // 5 // Copyright 2010 Eric Niebler. Distributed under the Boost 6 // Software License, Version 1.0. (See accompanying file 7 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 8 9 #ifndef BOOST_PROTO_FUNCTIONAL_FUSION_REVERSE_HPP_EAN_11_27_2010 10 #define BOOST_PROTO_FUNCTIONAL_FUSION_REVERSE_HPP_EAN_11_27_2010 11 12 #include <boost/fusion/include/reverse.hpp> 13 #include <boost/proto/proto_fwd.hpp> 14 15 namespace boost { namespace proto { namespace functional 16 { 17 /// \brief A PolymorphicFunctionObject type that invokes the 18 /// \c fusion::reverse() algorithm on its argument. 19 /// 20 /// A PolymorphicFunctionObject type that invokes the 21 /// \c fusion::reverse() algorithm on its argument. This is 22 /// useful for defining a CallableTransform like \c reverse(_) 23 /// which reverses the order of the children of a Proto 24 /// expression node. 25 struct reverse 26 { 27 BOOST_PROTO_CALLABLE() 28 29 template<typename Sig> 30 struct result; 31 32 template<typename This, typename Seq> 33 struct result<This(Seq)> 34 : result<This(Seq const &)> 35 {}; 36 37 template<typename This, typename Seq> 38 struct result<This(Seq &)> 39 : fusion::result_of::reverse<Seq> 40 {}; 41 42 template<typename Seq> 43 typename fusion::result_of::reverse<Seq>::type operator ()boost::proto::functional::reverse44 operator ()(Seq &seq) const 45 { 46 // Work around a const-correctness issue in Fusion 47 typedef typename fusion::result_of::reverse<Seq>::type result_type; 48 return result_type(seq); 49 } 50 51 template<typename Seq> 52 typename fusion::result_of::reverse<Seq const>::type operator ()boost::proto::functional::reverse53 operator ()(Seq const &seq) const 54 { 55 return fusion::reverse(seq); 56 } 57 }; 58 }}} 59 60 #endif 61