ceph/src/boost/libs/compute/include/boost/compute/lambda/result_of.hpp

   1 //---------------------------------------------------------------------------//
   2 // Copyright (c) 2013 Kyle Lutz <kyle.r.lutz@gmail.com>
   3 //
   4 // Distributed under the Boost Software License, Version 1.0
   5 // See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt
   7 //
   8 // See http://boostorg.github.com/compute for more information.
   9 //---------------------------------------------------------------------------//
  10
  11 #ifndef BOOST_COMPUTE_LAMBDA_RESULT_OF_HPP
  12 #define BOOST_COMPUTE_LAMBDA_RESULT_OF_HPP
  13
  14 #include <boost/mpl/vector.hpp>
  15 #include <boost/proto/proto.hpp>
  16
  17 #include <boost/compute/type_traits/common_type.hpp>
  18
  19 namespace boost {
  20 namespace compute {
  21 namespace lambda {
  22
  23 namespace mpl = boost::mpl;
  24 namespace proto = boost::proto;
  25
  26 // meta-function returning the result type of a lambda expression
  27 template<class Expr,
  28          class Args = void,
  29          class Tags = typename proto::tag_of<Expr>::type>
  30 struct result_of
  31 {
  32 };
  33
  34 // terminals
  35 template<class Expr, class Args>
  36 struct result_of<Expr, Args, proto::tag::terminal>
  37 {
  38     typedef typename proto::result_of::value<Expr>::type type;
  39 };
  40
  41 // binary operators
  42 #define BOOST_COMPUTE_LAMBDA_RESULT_OF_BINARY_OPERATOR(tag) \
  43     template<class Expr, class Args> \
  44     struct result_of<Expr, Args, tag> \
  45     { \
  46         typedef typename proto::result_of::child_c<Expr, 0>::type left; \
  47         typedef typename proto::result_of::child_c<Expr, 1>::type right; \
  48         \
  49         typedef typename boost::common_type< \
  50             typename ::boost::compute::lambda::result_of< \
  51                          left, \
  52                          Args, \
  53                          typename proto::tag_of<left>::type>::type, \
  54             typename ::boost::compute::lambda::result_of< \
  55                          right, \
  56                          Args, \
  57                          typename proto::tag_of<right>::type>::type \
  58          >::type type; \
  59     };
  60
  61 BOOST_COMPUTE_LAMBDA_RESULT_OF_BINARY_OPERATOR(proto::tag::plus)
  62 BOOST_COMPUTE_LAMBDA_RESULT_OF_BINARY_OPERATOR(proto::tag::minus)
  63 BOOST_COMPUTE_LAMBDA_RESULT_OF_BINARY_OPERATOR(proto::tag::multiplies)
  64 BOOST_COMPUTE_LAMBDA_RESULT_OF_BINARY_OPERATOR(proto::tag::divides)
  65 BOOST_COMPUTE_LAMBDA_RESULT_OF_BINARY_OPERATOR(proto::tag::modulus)
  66 BOOST_COMPUTE_LAMBDA_RESULT_OF_BINARY_OPERATOR(proto::tag::bitwise_and)
  67 BOOST_COMPUTE_LAMBDA_RESULT_OF_BINARY_OPERATOR(proto::tag::bitwise_or)
  68 BOOST_COMPUTE_LAMBDA_RESULT_OF_BINARY_OPERATOR(proto::tag::bitwise_xor)
  69
  70 // comparision operators
  71 #define BOOST_COMPUTE_LAMBDA_RESULT_OF_COMPARISON_OPERATOR(tag) \
  72     template<class Expr, class Args> \
  73     struct result_of<Expr, Args, tag> \
  74     { \
  75         typedef bool type; \
  76     };
  77
  78 BOOST_COMPUTE_LAMBDA_RESULT_OF_COMPARISON_OPERATOR(proto::tag::less)
  79 BOOST_COMPUTE_LAMBDA_RESULT_OF_COMPARISON_OPERATOR(proto::tag::greater)
  80 BOOST_COMPUTE_LAMBDA_RESULT_OF_COMPARISON_OPERATOR(proto::tag::less_equal)
  81 BOOST_COMPUTE_LAMBDA_RESULT_OF_COMPARISON_OPERATOR(proto::tag::greater_equal)
  82 BOOST_COMPUTE_LAMBDA_RESULT_OF_COMPARISON_OPERATOR(proto::tag::equal_to)
  83 BOOST_COMPUTE_LAMBDA_RESULT_OF_COMPARISON_OPERATOR(proto::tag::not_equal_to)
  84 BOOST_COMPUTE_LAMBDA_RESULT_OF_COMPARISON_OPERATOR(proto::tag::logical_and)
  85 BOOST_COMPUTE_LAMBDA_RESULT_OF_COMPARISON_OPERATOR(proto::tag::logical_or)
  86
  87 // assignment operator
  88 template<class Expr, class Args>
  89 struct result_of<Expr, Args, proto::tag::assign>
  90 {
  91     typedef typename proto::result_of::child_c<Expr, 0>::type left;
  92     typedef typename proto::result_of::child_c<Expr, 1>::type right;
  93
  94     typedef typename ::boost::compute::lambda::result_of<
  95         right, Args, typename proto::tag_of<right>::type
  96     >::type type;
  97 };
  98
  99 // functions
 100 template<class Expr, class Args>
 101 struct result_of<Expr, Args, proto::tag::function>
 102 {
 103     typedef typename proto::result_of::child_c<Expr, 0>::type func_expr;
 104     typedef typename proto::result_of::value<func_expr>::type func;
 105
 106     typedef typename func::template lambda_result<Expr, Args>::type type;
 107 };
 108
 109 } // end lambda namespace
 110 } // end compute namespace
 111 } // end boost namespace
 112
 113 #endif // BOOST_COMPUTE_LAMBDA_RESULT_OF_HPP