boost/spirit/home/phoenix/operator/detail/binary_eval.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2007 Joel de Guzman
   3
   4     Distributed under the Boost Software License, Version 1.0. (See accompanying
   5     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 ==============================================================================*/
   7 #ifndef PHOENIX_OPERATOR_DETAIL_BINARY_EVAL_HPP
   8 #define PHOENIX_OPERATOR_DETAIL_BINARY_EVAL_HPP
   9
  10 #include <boost/mpl/or.hpp>
  11 #include <boost/mpl/eval_if.hpp>
  12 #include <boost/mpl/identity.hpp>
  13 #include <boost/type_traits/is_same.hpp>
  14 #include <boost/spirit/home/phoenix/core/compose.hpp>
  15
  16 #define PHOENIX_BINARY_EVAL(eval_name, op_result, expr)                         \
  17     struct eval_name                                                            \
  18     {                                                                           \
  19         template <typename Env, typename A0, typename A1>                       \
  20         struct result                                                            \
  21         {                                                                       \
  22             typedef typename A0::template result<Env>::type x_type;              \
  23             typedef typename A1::template result<Env>::type y_type;              \
  24                                                                                 \
  25             typedef typename                                                    \
  26                 mpl::eval_if<                                                   \
  27                     mpl::or_<is_actor<x_type>, is_actor<y_type> >               \
  28                   , re_curry<eval_name, x_type, y_type>                         \
  29                   , op_result<x_type, y_type>                                   \
  30                 >::type                                                         \
  31             type;                                                               \
  32         };                                                                      \
  33                                                                                 \
  34         template <typename RT, typename Env, typename A0, typename A1>          \
  35         static RT                                                               \
  36         eval(Env const& env, A0& a0, A1& a1)                                    \
  37         {                                                                       \
  38             return expr;                                                        \
  39         }                                                                       \
  40     };
  41
  42 #undef x
  43 #undef y
  44 #endif