boost/proto/context/default.hpp
/////////////////////////////////////////////////////////////////////////////// /// \file default.hpp /// Definintion of default_context, a default evaluation context for /// proto::eval() that uses Boost.Typeof to deduce return types /// of the built-in operators. // // Copyright 2008 Eric Niebler. 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_PROTO_CONTEXT_DEFAULT_HPP_EAN_01_08_2007 #define BOOST_PROTO_CONTEXT_DEFAULT_HPP_EAN_01_08_2007 #include <boost/config.hpp> #include <boost/preprocessor/arithmetic/add.hpp> #include <boost/preprocessor/arithmetic/sub.hpp> #include <boost/preprocessor/iteration/iterate.hpp> #include <boost/preprocessor/repetition/enum.hpp> #include <boost/preprocessor/repetition/enum_shifted.hpp> #include <boost/utility/result_of.hpp> #include <boost/type_traits/is_const.hpp> #include <boost/type_traits/is_function.hpp> #include <boost/type_traits/remove_reference.hpp> #include <boost/type_traits/is_member_pointer.hpp> #include <boost/type_traits/is_member_object_pointer.hpp> #include <boost/type_traits/is_member_function_pointer.hpp> #include <boost/proto/proto_fwd.hpp> #include <boost/proto/tags.hpp> #include <boost/proto/eval.hpp> #include <boost/proto/traits.hpp> // for proto::child_c() #include <boost/proto/detail/decltype.hpp> namespace boost { namespace proto { /// INTERNAL ONLY /// #define UNREF(x) typename boost::remove_reference<x>::type namespace context { template< typename Expr , typename Context , typename Tag // = typename Expr::proto_tag , long Arity // = Expr::proto_arity_c > struct default_eval {}; template<typename Expr, typename Context> struct default_eval<Expr, Context, tag::terminal, 0> { typedef typename proto::result_of::value<Expr &>::type result_type; result_type operator ()(Expr &expr, Context &) const { return proto::value(expr); } }; /// INTERNAL ONLY /// #define BOOST_PROTO_UNARY_DEFAULT_EVAL(OP, TAG, MAKE) \ template<typename Expr, typename Context> \ struct default_eval<Expr, Context, TAG, 1> \ { \ private: \ typedef typename proto::result_of::child_c<Expr, 0>::type e0; \ typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0; \ public: \ BOOST_PROTO_DECLTYPE_(OP proto::detail::MAKE<r0>(), result_type) \ result_type operator ()(Expr &expr, Context &ctx) const \ { \ return OP proto::eval(proto::child_c<0>(expr), ctx); \ } \ }; \ /**/ /// INTERNAL ONLY /// #define BOOST_PROTO_BINARY_DEFAULT_EVAL(OP, TAG, LMAKE, RMAKE) \ template<typename Expr, typename Context> \ struct default_eval<Expr, Context, TAG, 2> \ { \ private: \ typedef typename proto::result_of::child_c<Expr, 0>::type e0; \ typedef typename proto::result_of::child_c<Expr, 1>::type e1; \ typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0; \ typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1; \ public: \ BOOST_PROTO_DECLTYPE_( \ proto::detail::LMAKE<r0>() OP proto::detail::RMAKE<r1>() \ , result_type \ ) \ result_type operator ()(Expr &expr, Context &ctx) const \ { \ return proto::eval( \ proto::child_c<0>(expr), ctx) OP proto::eval(proto::child_c<1>(expr) \ , ctx \ ); \ } \ }; \ /**/ BOOST_PROTO_UNARY_DEFAULT_EVAL(+, proto::tag::unary_plus, make) BOOST_PROTO_UNARY_DEFAULT_EVAL(-, proto::tag::negate, make) BOOST_PROTO_UNARY_DEFAULT_EVAL(*, proto::tag::dereference, make) BOOST_PROTO_UNARY_DEFAULT_EVAL(~, proto::tag::complement, make) BOOST_PROTO_UNARY_DEFAULT_EVAL(&, proto::tag::address_of, make) BOOST_PROTO_UNARY_DEFAULT_EVAL(!, proto::tag::logical_not, make) BOOST_PROTO_UNARY_DEFAULT_EVAL(++, proto::tag::pre_inc, make_mutable) BOOST_PROTO_UNARY_DEFAULT_EVAL(--, proto::tag::pre_dec, make_mutable) BOOST_PROTO_BINARY_DEFAULT_EVAL(<<, proto::tag::shift_left, make_mutable, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(>>, proto::tag::shift_right, make_mutable, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(*, proto::tag::multiplies, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(/, proto::tag::divides, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(%, proto::tag::modulus, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(+, proto::tag::plus, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(-, proto::tag::minus, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(<, proto::tag::less, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(>, proto::tag::greater, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(<=, proto::tag::less_equal, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(>=, proto::tag::greater_equal, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(==, proto::tag::equal_to, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(!=, proto::tag::not_equal_to, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(||, proto::tag::logical_or, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(&&, proto::tag::logical_and, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(&, proto::tag::bitwise_and, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(|, proto::tag::bitwise_or, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(^, proto::tag::bitwise_xor, make, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(=, proto::tag::assign, make_mutable, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(<<=, proto::tag::shift_left_assign, make_mutable, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(>>=, proto::tag::shift_right_assign, make_mutable, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(*=, proto::tag::multiplies_assign, make_mutable, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(/=, proto::tag::divides_assign, make_mutable, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(%=, proto::tag::modulus_assign, make_mutable, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(+=, proto::tag::plus_assign, make_mutable, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(-=, proto::tag::minus_assign, make_mutable, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(&=, proto::tag::bitwise_and_assign, make_mutable, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(|=, proto::tag::bitwise_or_assign, make_mutable, make) BOOST_PROTO_BINARY_DEFAULT_EVAL(^=, proto::tag::bitwise_xor_assign, make_mutable, make) #undef BOOST_PROTO_UNARY_DEFAULT_EVAL #undef BOOST_PROTO_BINARY_DEFAULT_EVAL /// INTERNAL ONLY template<typename Expr, typename Context> struct is_member_function_eval : is_member_function_pointer< typename detail::uncvref< typename proto::result_of::eval< typename remove_reference< typename proto::result_of::child_c<Expr, 1>::type >::type , Context >::type >::type > {}; /// INTERNAL ONLY template<typename Expr, typename Context, bool IsMemFunCall> struct memfun_eval { private: typedef typename result_of::child_c<Expr, 0>::type e0; typedef typename result_of::child_c<Expr, 1>::type e1; typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0; typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1; public: typedef typename detail::mem_ptr_fun<r0, r1>::result_type result_type; result_type operator ()(Expr &expr, Context &ctx) const { return detail::mem_ptr_fun<r0, r1>()( proto::eval(proto::child_c<0>(expr), ctx) , proto::eval(proto::child_c<1>(expr), ctx) ); } }; /// INTERNAL ONLY template<typename Expr, typename Context> struct memfun_eval<Expr, Context, true> { private: typedef typename result_of::child_c<Expr, 0>::type e0; typedef typename result_of::child_c<Expr, 1>::type e1; typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0; typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1; public: typedef detail::memfun<r0, r1> result_type; result_type const operator ()(Expr &expr, Context &ctx) const { return detail::memfun<r0, r1>( proto::eval(proto::child_c<0>(expr), ctx) , proto::eval(proto::child_c<1>(expr), ctx) ); } }; template<typename Expr, typename Context> struct default_eval<Expr, Context, tag::mem_ptr, 2> : memfun_eval<Expr, Context, is_member_function_eval<Expr, Context>::value> {}; // Handle post-increment specially. template<typename Expr, typename Context> struct default_eval<Expr, Context, proto::tag::post_inc, 1> { private: typedef typename proto::result_of::child_c<Expr, 0>::type e0; typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0; public: BOOST_PROTO_DECLTYPE_(proto::detail::make_mutable<r0>() ++, result_type) result_type operator ()(Expr &expr, Context &ctx) const { return proto::eval(proto::child_c<0>(expr), ctx) ++; } }; // Handle post-decrement specially. template<typename Expr, typename Context> struct default_eval<Expr, Context, proto::tag::post_dec, 1> { private: typedef typename proto::result_of::child_c<Expr, 0>::type e0; typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0; public: BOOST_PROTO_DECLTYPE_(proto::detail::make_mutable<r0>() --, result_type) result_type operator ()(Expr &expr, Context &ctx) const { return proto::eval(proto::child_c<0>(expr), ctx) --; } }; // Handle subscript specially. template<typename Expr, typename Context> struct default_eval<Expr, Context, proto::tag::subscript, 2> { private: typedef typename proto::result_of::child_c<Expr, 0>::type e0; typedef typename proto::result_of::child_c<Expr, 1>::type e1; typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0; typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1; public: BOOST_PROTO_DECLTYPE_(proto::detail::make_subscriptable<r0>()[proto::detail::make<r1>()], result_type) result_type operator ()(Expr &expr, Context &ctx) const { return proto::eval(proto::child_c<0>(expr), ctx)[proto::eval(proto::child_c<1>(expr), ctx)]; } }; // Handle if_else_ specially. template<typename Expr, typename Context> struct default_eval<Expr, Context, proto::tag::if_else_, 3> { private: typedef typename proto::result_of::child_c<Expr, 0>::type e0; typedef typename proto::result_of::child_c<Expr, 1>::type e1; typedef typename proto::result_of::child_c<Expr, 2>::type e2; typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0; typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1; typedef typename proto::result_of::eval<UNREF(e2), Context>::type r2; public: BOOST_PROTO_DECLTYPE_( proto::detail::make<r0>() ? proto::detail::make<r1>() : proto::detail::make<r2>() , result_type ) result_type operator ()(Expr &expr, Context &ctx) const { return proto::eval(proto::child_c<0>(expr), ctx) ? proto::eval(proto::child_c<1>(expr), ctx) : proto::eval(proto::child_c<2>(expr), ctx); } }; // Handle comma specially. template<typename Expr, typename Context> struct default_eval<Expr, Context, proto::tag::comma, 2> { private: typedef typename proto::result_of::child_c<Expr, 0>::type e0; typedef typename proto::result_of::child_c<Expr, 1>::type e1; typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0; typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1; public: typedef typename proto::detail::comma_result<r0, r1>::type result_type; result_type operator ()(Expr &expr, Context &ctx) const { return proto::eval(proto::child_c<0>(expr), ctx), proto::eval(proto::child_c<1>(expr), ctx); } }; // Handle function specially #define BOOST_PROTO_DEFAULT_EVAL_TYPE(Z, N, DATA) \ typename proto::result_of::eval< \ typename remove_reference< \ typename proto::result_of::child_c<DATA, N>::type \ >::type \ , Context \ >::type \ /**/ #define BOOST_PROTO_DEFAULT_EVAL(Z, N, DATA) \ proto::eval(proto::child_c<N>(DATA), context) \ /**/ template<typename Expr, typename Context> struct default_eval<Expr, Context, proto::tag::function, 1> { typedef typename proto::detail::result_of_fixup< BOOST_PROTO_DEFAULT_EVAL_TYPE(~, 0, Expr) >::type function_type; typedef typename BOOST_PROTO_RESULT_OF<function_type()>::type result_type; result_type operator ()(Expr &expr, Context &context) const { return BOOST_PROTO_DEFAULT_EVAL(~, 0, expr)(); } }; template<typename Expr, typename Context> struct default_eval<Expr, Context, proto::tag::function, 2> { typedef typename proto::detail::result_of_fixup< BOOST_PROTO_DEFAULT_EVAL_TYPE(~, 0, Expr) >::type function_type; typedef typename detail::result_of_< function_type(BOOST_PROTO_DEFAULT_EVAL_TYPE(~, 1, Expr)) >::type result_type; result_type operator ()(Expr &expr, Context &context) const { return this->invoke( expr , context , is_member_function_pointer<function_type>() , is_member_object_pointer<function_type>() ); } private: result_type invoke(Expr &expr, Context &context, mpl::false_, mpl::false_) const { return BOOST_PROTO_DEFAULT_EVAL(~, 0, expr)(BOOST_PROTO_DEFAULT_EVAL(~, 1, expr)); } result_type invoke(Expr &expr, Context &context, mpl::true_, mpl::false_) const { BOOST_PROTO_USE_GET_POINTER(); typedef typename detail::classtypeof<function_type>::type class_type; return ( BOOST_PROTO_GET_POINTER(class_type, BOOST_PROTO_DEFAULT_EVAL(~, 1, expr)) ->* BOOST_PROTO_DEFAULT_EVAL(~, 0, expr) )(); } result_type invoke(Expr &expr, Context &context, mpl::false_, mpl::true_) const { BOOST_PROTO_USE_GET_POINTER(); typedef typename detail::classtypeof<function_type>::type class_type; return ( BOOST_PROTO_GET_POINTER(class_type, BOOST_PROTO_DEFAULT_EVAL(~, 1, expr)) ->* BOOST_PROTO_DEFAULT_EVAL(~, 0, expr) ); } }; // Additional specialization are generated by the preprocessor #include <boost/proto/context/detail/default_eval.hpp> #undef BOOST_PROTO_DEFAULT_EVAL_TYPE #undef BOOST_PROTO_DEFAULT_EVAL /// default_context /// struct default_context { /// default_context::eval /// template<typename Expr, typename ThisContext = default_context const> struct eval : default_eval<Expr, ThisContext> {}; }; } // namespace context }} // namespace boost::proto #undef UNREF #endif