Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: /// \file default.hpp
Chris@16: /// Definintion of default_context, a default evaluation context for
Chris@16: /// proto::eval() that uses Boost.Typeof to deduce return types
Chris@16: /// of the built-in operators.
Chris@16: //
Chris@16: //  Copyright 2008 Eric Niebler. Distributed under the Boost
Chris@16: //  Software License, Version 1.0. (See accompanying file
Chris@16: //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_PROTO_CONTEXT_DEFAULT_HPP_EAN_01_08_2007
Chris@16: #define BOOST_PROTO_CONTEXT_DEFAULT_HPP_EAN_01_08_2007
Chris@16: 
Chris@16: #include <boost/config.hpp>
Chris@16: #include <boost/preprocessor/arithmetic/add.hpp>
Chris@16: #include <boost/preprocessor/arithmetic/sub.hpp>
Chris@16: #include <boost/preprocessor/iteration/iterate.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_shifted.hpp>
Chris@16: #include <boost/utility/result_of.hpp>
Chris@16: #include <boost/type_traits/is_const.hpp>
Chris@16: #include <boost/type_traits/is_function.hpp>
Chris@16: #include <boost/type_traits/remove_reference.hpp>
Chris@16: #include <boost/type_traits/is_member_pointer.hpp>
Chris@16: #include <boost/type_traits/is_member_object_pointer.hpp>
Chris@16: #include <boost/type_traits/is_member_function_pointer.hpp>
Chris@16: #include <boost/proto/proto_fwd.hpp>
Chris@16: #include <boost/proto/tags.hpp>
Chris@16: #include <boost/proto/eval.hpp>
Chris@16: #include <boost/proto/traits.hpp> // for proto::child_c()
Chris@16: #include <boost/proto/detail/decltype.hpp>
Chris@16: 
Chris@16: namespace boost { namespace proto
Chris@16: {
Chris@16: /// INTERNAL ONLY
Chris@16: ///
Chris@16: #define UNREF(x) typename boost::remove_reference<x>::type
Chris@16: 
Chris@16:     namespace context
Chris@16:     {
Chris@16:         template<
Chris@16:             typename Expr
Chris@16:           , typename Context
Chris@16:           , typename Tag        // = typename Expr::proto_tag
Chris@16:           , long Arity          // = Expr::proto_arity_c
Chris@16:         >
Chris@16:         struct default_eval
Chris@16:         {};
Chris@16: 
Chris@16:         template<typename Expr, typename Context>
Chris@16:         struct default_eval<Expr, Context, tag::terminal, 0>
Chris@16:         {
Chris@16:             typedef
Chris@16:                 typename proto::result_of::value<Expr &>::type
Chris@16:             result_type;
Chris@16: 
Chris@16:             result_type operator ()(Expr &expr, Context &) const
Chris@16:             {
Chris@16:                 return proto::value(expr);
Chris@16:             }
Chris@16:         };
Chris@16: 
Chris@16:         /// INTERNAL ONLY
Chris@16:         ///
Chris@16:     #define BOOST_PROTO_UNARY_DEFAULT_EVAL(OP, TAG, MAKE)                                       \
Chris@16:         template<typename Expr, typename Context>                                               \
Chris@16:         struct default_eval<Expr, Context, TAG, 1>                                              \
Chris@16:         {                                                                                       \
Chris@16:         private:                                                                                \
Chris@16:             typedef typename proto::result_of::child_c<Expr, 0>::type e0;                       \
Chris@16:             typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;               \
Chris@16:         public:                                                                                 \
Chris@16:             BOOST_PROTO_DECLTYPE_(OP proto::detail::MAKE<r0>(), result_type)                    \
Chris@16:             result_type operator ()(Expr &expr, Context &ctx) const                             \
Chris@16:             {                                                                                   \
Chris@16:                 return OP proto::eval(proto::child_c<0>(expr), ctx);                            \
Chris@16:             }                                                                                   \
Chris@16:         };                                                                                      \
Chris@16:         /**/
Chris@16: 
Chris@16:         /// INTERNAL ONLY
Chris@16:         ///
Chris@16:     #define BOOST_PROTO_BINARY_DEFAULT_EVAL(OP, TAG, LMAKE, RMAKE)                              \
Chris@16:         template<typename Expr, typename Context>                                               \
Chris@16:         struct default_eval<Expr, Context, TAG, 2>                                              \
Chris@16:         {                                                                                       \
Chris@16:         private:                                                                                \
Chris@16:             typedef typename proto::result_of::child_c<Expr, 0>::type e0;                       \
Chris@16:             typedef typename proto::result_of::child_c<Expr, 1>::type e1;                       \
Chris@16:             typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;               \
Chris@16:             typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1;               \
Chris@16:         public:                                                                                 \
Chris@16:             BOOST_PROTO_DECLTYPE_(                                                              \
Chris@16:                 proto::detail::LMAKE<r0>() OP proto::detail::RMAKE<r1>()                        \
Chris@16:               , result_type                                                                     \
Chris@16:             )                                                                                   \
Chris@16:             result_type operator ()(Expr &expr, Context &ctx) const                             \
Chris@16:             {                                                                                   \
Chris@16:                 return proto::eval(                                                             \
Chris@16:                     proto::child_c<0>(expr), ctx) OP proto::eval(proto::child_c<1>(expr)        \
Chris@16:                   , ctx                                                                         \
Chris@16:                 );                                                                              \
Chris@16:             }                                                                                   \
Chris@16:         };                                                                                      \
Chris@16:         /**/
Chris@16: 
Chris@16:         BOOST_PROTO_UNARY_DEFAULT_EVAL(+, proto::tag::unary_plus, make)
Chris@16:         BOOST_PROTO_UNARY_DEFAULT_EVAL(-, proto::tag::negate, make)
Chris@16:         BOOST_PROTO_UNARY_DEFAULT_EVAL(*, proto::tag::dereference, make)
Chris@16:         BOOST_PROTO_UNARY_DEFAULT_EVAL(~, proto::tag::complement, make)
Chris@16:         BOOST_PROTO_UNARY_DEFAULT_EVAL(&, proto::tag::address_of, make)
Chris@16:         BOOST_PROTO_UNARY_DEFAULT_EVAL(!, proto::tag::logical_not, make)
Chris@16:         BOOST_PROTO_UNARY_DEFAULT_EVAL(++, proto::tag::pre_inc, make_mutable)
Chris@16:         BOOST_PROTO_UNARY_DEFAULT_EVAL(--, proto::tag::pre_dec, make_mutable)
Chris@16: 
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(<<, proto::tag::shift_left, make_mutable, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(>>, proto::tag::shift_right, make_mutable, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(*, proto::tag::multiplies, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(/, proto::tag::divides, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(%, proto::tag::modulus, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(+, proto::tag::plus, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(-, proto::tag::minus, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(<, proto::tag::less, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(>, proto::tag::greater, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(<=, proto::tag::less_equal, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(>=, proto::tag::greater_equal, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(==, proto::tag::equal_to, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(!=, proto::tag::not_equal_to, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(||, proto::tag::logical_or, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(&&, proto::tag::logical_and, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(&, proto::tag::bitwise_and, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(|, proto::tag::bitwise_or, make, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(^, proto::tag::bitwise_xor, make, make)
Chris@16: 
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(=, proto::tag::assign, make_mutable, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(<<=, proto::tag::shift_left_assign, make_mutable, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(>>=, proto::tag::shift_right_assign, make_mutable, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(*=, proto::tag::multiplies_assign, make_mutable, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(/=, proto::tag::divides_assign, make_mutable, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(%=, proto::tag::modulus_assign, make_mutable, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(+=, proto::tag::plus_assign, make_mutable, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(-=, proto::tag::minus_assign, make_mutable, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(&=, proto::tag::bitwise_and_assign, make_mutable, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(|=, proto::tag::bitwise_or_assign, make_mutable, make)
Chris@16:         BOOST_PROTO_BINARY_DEFAULT_EVAL(^=, proto::tag::bitwise_xor_assign, make_mutable, make)
Chris@16: 
Chris@16:     #undef BOOST_PROTO_UNARY_DEFAULT_EVAL
Chris@16:     #undef BOOST_PROTO_BINARY_DEFAULT_EVAL
Chris@16: 
Chris@16:         /// INTERNAL ONLY
Chris@16:         template<typename Expr, typename Context>
Chris@16:         struct is_member_function_eval
Chris@16:           : is_member_function_pointer<
Chris@16:                 typename detail::uncvref<
Chris@16:                     typename proto::result_of::eval<
Chris@16:                         typename remove_reference<
Chris@16:                             typename proto::result_of::child_c<Expr, 1>::type
Chris@16:                         >::type
Chris@16:                       , Context
Chris@16:                     >::type
Chris@16:                 >::type
Chris@16:             >
Chris@16:         {};
Chris@16: 
Chris@16:         /// INTERNAL ONLY
Chris@16:         template<typename Expr, typename Context, bool IsMemFunCall>
Chris@16:         struct memfun_eval
Chris@16:         {
Chris@16:         private:
Chris@16:             typedef typename result_of::child_c<Expr, 0>::type e0;
Chris@16:             typedef typename result_of::child_c<Expr, 1>::type e1;
Chris@16:             typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;
Chris@16:             typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1;
Chris@16:         public:
Chris@16:             typedef typename detail::mem_ptr_fun<r0, r1>::result_type result_type;
Chris@16:             result_type operator ()(Expr &expr, Context &ctx) const
Chris@16:             {
Chris@16:                 return detail::mem_ptr_fun<r0, r1>()(
Chris@16:                     proto::eval(proto::child_c<0>(expr), ctx)
Chris@16:                   , proto::eval(proto::child_c<1>(expr), ctx)
Chris@16:                 );
Chris@16:             }
Chris@16:         };
Chris@16: 
Chris@16:         /// INTERNAL ONLY
Chris@16:         template<typename Expr, typename Context>
Chris@16:         struct memfun_eval<Expr, Context, true>
Chris@16:         {
Chris@16:         private:
Chris@16:             typedef typename result_of::child_c<Expr, 0>::type e0;
Chris@16:             typedef typename result_of::child_c<Expr, 1>::type e1;
Chris@16:             typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;
Chris@16:             typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1;
Chris@16:         public:
Chris@16:             typedef detail::memfun<r0, r1> result_type;
Chris@16:             result_type const operator ()(Expr &expr, Context &ctx) const
Chris@16:             {
Chris@16:                 return detail::memfun<r0, r1>(
Chris@16:                     proto::eval(proto::child_c<0>(expr), ctx)
Chris@16:                   , proto::eval(proto::child_c<1>(expr), ctx)
Chris@16:                 );
Chris@16:             }
Chris@16:         };
Chris@16: 
Chris@16:         template<typename Expr, typename Context>
Chris@16:         struct default_eval<Expr, Context, tag::mem_ptr, 2>
Chris@16:           : memfun_eval<Expr, Context, is_member_function_eval<Expr, Context>::value>
Chris@16:         {};
Chris@16: 
Chris@16:         // Handle post-increment specially.
Chris@16:         template<typename Expr, typename Context>
Chris@16:         struct default_eval<Expr, Context, proto::tag::post_inc, 1>
Chris@16:         {
Chris@16:         private:
Chris@16:             typedef typename proto::result_of::child_c<Expr, 0>::type e0;
Chris@16:             typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;
Chris@16:         public:
Chris@16:             BOOST_PROTO_DECLTYPE_(proto::detail::make_mutable<r0>() ++, result_type)
Chris@16:             result_type operator ()(Expr &expr, Context &ctx) const
Chris@16:             {
Chris@16:                 return proto::eval(proto::child_c<0>(expr), ctx) ++;
Chris@16:             }
Chris@16:         };
Chris@16: 
Chris@16:         // Handle post-decrement specially.
Chris@16:         template<typename Expr, typename Context>
Chris@16:         struct default_eval<Expr, Context, proto::tag::post_dec, 1>
Chris@16:         {
Chris@16:         private:
Chris@16:             typedef typename proto::result_of::child_c<Expr, 0>::type e0;
Chris@16:             typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;
Chris@16:         public:
Chris@16:             BOOST_PROTO_DECLTYPE_(proto::detail::make_mutable<r0>() --, result_type)
Chris@16:             result_type operator ()(Expr &expr, Context &ctx) const
Chris@16:             {
Chris@16:                 return proto::eval(proto::child_c<0>(expr), ctx) --;
Chris@16:             }
Chris@16:         };
Chris@16: 
Chris@16:         // Handle subscript specially.
Chris@16:         template<typename Expr, typename Context>
Chris@16:         struct default_eval<Expr, Context, proto::tag::subscript, 2>
Chris@16:         {
Chris@16:         private:
Chris@16:             typedef typename proto::result_of::child_c<Expr, 0>::type e0;
Chris@16:             typedef typename proto::result_of::child_c<Expr, 1>::type e1;
Chris@16:             typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;
Chris@16:             typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1;
Chris@16:         public:
Chris@16:             BOOST_PROTO_DECLTYPE_(proto::detail::make_subscriptable<r0>()[proto::detail::make<r1>()], result_type)
Chris@16:             result_type operator ()(Expr &expr, Context &ctx) const
Chris@16:             {
Chris@16:                 return proto::eval(proto::child_c<0>(expr), ctx)[proto::eval(proto::child_c<1>(expr), ctx)];
Chris@16:             }
Chris@16:         };
Chris@16: 
Chris@16:         // Handle if_else_ specially.
Chris@16:         template<typename Expr, typename Context>
Chris@16:         struct default_eval<Expr, Context, proto::tag::if_else_, 3>
Chris@16:         {
Chris@16:         private:
Chris@16:             typedef typename proto::result_of::child_c<Expr, 0>::type e0;
Chris@16:             typedef typename proto::result_of::child_c<Expr, 1>::type e1;
Chris@16:             typedef typename proto::result_of::child_c<Expr, 2>::type e2;
Chris@16:             typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;
Chris@16:             typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1;
Chris@16:             typedef typename proto::result_of::eval<UNREF(e2), Context>::type r2;
Chris@16:         public:
Chris@16:             BOOST_PROTO_DECLTYPE_(
Chris@16:                 proto::detail::make<r0>()
Chris@16:               ? proto::detail::make<r1>()
Chris@16:               : proto::detail::make<r2>()
Chris@16:               , result_type
Chris@16:             )
Chris@16:             result_type operator ()(Expr &expr, Context &ctx) const
Chris@16:             {
Chris@16:                 return proto::eval(proto::child_c<0>(expr), ctx)
Chris@16:                       ? proto::eval(proto::child_c<1>(expr), ctx)
Chris@16:                       : proto::eval(proto::child_c<2>(expr), ctx);
Chris@16:             }
Chris@16:         };
Chris@16: 
Chris@16:         // Handle comma specially.
Chris@16:         template<typename Expr, typename Context>
Chris@16:         struct default_eval<Expr, Context, proto::tag::comma, 2>
Chris@16:         {
Chris@16:         private:
Chris@16:             typedef typename proto::result_of::child_c<Expr, 0>::type e0;
Chris@16:             typedef typename proto::result_of::child_c<Expr, 1>::type e1;
Chris@16:             typedef typename proto::result_of::eval<UNREF(e0), Context>::type r0;
Chris@16:             typedef typename proto::result_of::eval<UNREF(e1), Context>::type r1;
Chris@16:         public:
Chris@16:             typedef typename proto::detail::comma_result<r0, r1>::type result_type;
Chris@16:             result_type operator ()(Expr &expr, Context &ctx) const
Chris@16:             {
Chris@16:                 return proto::eval(proto::child_c<0>(expr), ctx), proto::eval(proto::child_c<1>(expr), ctx);
Chris@16:             }
Chris@16:         };
Chris@16: 
Chris@16:         // Handle function specially
Chris@16:         #define BOOST_PROTO_DEFAULT_EVAL_TYPE(Z, N, DATA)                                       \
Chris@16:             typename proto::result_of::eval<                                                    \
Chris@16:                 typename remove_reference<                                                      \
Chris@16:                     typename proto::result_of::child_c<DATA, N>::type                           \
Chris@16:                 >::type                                                                         \
Chris@16:               , Context                                                                         \
Chris@16:             >::type                                                                             \
Chris@16:             /**/
Chris@16: 
Chris@16:         #define BOOST_PROTO_DEFAULT_EVAL(Z, N, DATA)                                            \
Chris@16:             proto::eval(proto::child_c<N>(DATA), context)                                       \
Chris@16:             /**/
Chris@16: 
Chris@16:         template<typename Expr, typename Context>
Chris@16:         struct default_eval<Expr, Context, proto::tag::function, 1>
Chris@16:         {
Chris@16:             typedef
Chris@16:                 typename proto::detail::result_of_fixup<
Chris@16:                     BOOST_PROTO_DEFAULT_EVAL_TYPE(~, 0, Expr)
Chris@16:                 >::type
Chris@16:             function_type;
Chris@16: 
Chris@16:             typedef
Chris@16:                 typename BOOST_PROTO_RESULT_OF<function_type()>::type
Chris@16:             result_type;
Chris@16: 
Chris@16:             result_type operator ()(Expr &expr, Context &context) const
Chris@16:             {
Chris@16:                 return BOOST_PROTO_DEFAULT_EVAL(~, 0, expr)();
Chris@16:             }
Chris@16:         };
Chris@16: 
Chris@16:         template<typename Expr, typename Context>
Chris@16:         struct default_eval<Expr, Context, proto::tag::function, 2>
Chris@16:         {
Chris@16:             typedef
Chris@16:                 typename proto::detail::result_of_fixup<
Chris@16:                     BOOST_PROTO_DEFAULT_EVAL_TYPE(~, 0, Expr)
Chris@16:                 >::type
Chris@16:             function_type;
Chris@16: 
Chris@16:             typedef
Chris@16:                 typename detail::result_of_<
Chris@16:                     function_type(BOOST_PROTO_DEFAULT_EVAL_TYPE(~, 1, Expr))
Chris@16:                 >::type
Chris@16:             result_type;
Chris@16: 
Chris@16:             result_type operator ()(Expr &expr, Context &context) const
Chris@16:             {
Chris@16:                 return this->invoke(
Chris@16:                     expr
Chris@16:                   , context
Chris@16:                   , is_member_function_pointer<function_type>()
Chris@16:                   , is_member_object_pointer<function_type>()
Chris@16:                 );
Chris@16:             }
Chris@16: 
Chris@16:         private:
Chris@16:             result_type invoke(Expr &expr, Context &context, mpl::false_, mpl::false_) const
Chris@16:             {
Chris@16:                 return BOOST_PROTO_DEFAULT_EVAL(~, 0, expr)(BOOST_PROTO_DEFAULT_EVAL(~, 1, expr));
Chris@16:             }
Chris@16: 
Chris@16:             result_type invoke(Expr &expr, Context &context, mpl::true_, mpl::false_) const
Chris@16:             {
Chris@16:                 BOOST_PROTO_USE_GET_POINTER();
Chris@16:                 typedef typename detail::class_member_traits<function_type>::class_type class_type;
Chris@16:                 return (
Chris@16:                     BOOST_PROTO_GET_POINTER(class_type, (BOOST_PROTO_DEFAULT_EVAL(~, 1, expr))) ->* 
Chris@16:                     BOOST_PROTO_DEFAULT_EVAL(~, 0, expr)
Chris@16:                 )();
Chris@16:             }
Chris@16: 
Chris@16:             result_type invoke(Expr &expr, Context &context, mpl::false_, mpl::true_) const
Chris@16:             {
Chris@16:                 BOOST_PROTO_USE_GET_POINTER();
Chris@16:                 typedef typename detail::class_member_traits<function_type>::class_type class_type;
Chris@16:                 return (
Chris@16:                     BOOST_PROTO_GET_POINTER(class_type, (BOOST_PROTO_DEFAULT_EVAL(~, 1, expr))) ->*
Chris@16:                     BOOST_PROTO_DEFAULT_EVAL(~, 0, expr)
Chris@16:                 );
Chris@16:             }
Chris@16:         };
Chris@16: 
Chris@16:         // Additional specialization are generated by the preprocessor
Chris@16:         #include <boost/proto/context/detail/default_eval.hpp>
Chris@16: 
Chris@16:         #undef BOOST_PROTO_DEFAULT_EVAL_TYPE
Chris@16:         #undef BOOST_PROTO_DEFAULT_EVAL
Chris@16: 
Chris@16:         /// default_context
Chris@16:         ///
Chris@16:         struct default_context
Chris@16:         {
Chris@16:             /// default_context::eval
Chris@16:             ///
Chris@16:             template<typename Expr, typename ThisContext = default_context const>
Chris@16:             struct eval
Chris@16:               : default_eval<Expr, ThisContext>
Chris@16:             {};
Chris@16:         };
Chris@16: 
Chris@16:     } // namespace context
Chris@16: 
Chris@16: }} // namespace boost::proto
Chris@16: 
Chris@16: #undef UNREF
Chris@16: 
Chris@16: #endif