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

   1 //---------------------------------------------------------------------------//
   2 // Copyright (c) 2013-2014 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_MAKE_PAIR_HPP
  12 #define BOOST_COMPUTE_LAMBDA_MAKE_PAIR_HPP
  13
  14 #include <boost/compute/types/pair.hpp>
  15
  16 namespace boost {
  17 namespace compute {
  18 namespace lambda {
  19 namespace detail {
  20
  21 // function wrapper for make_pair() in lambda expressions
  22 struct make_pair_func
  23 {
  24     template<class Expr, class Args>
  25     struct lambda_result
  26     {
  27         typedef typename proto::result_of::child_c<Expr, 1>::type Arg1;
  28         typedef typename proto::result_of::child_c<Expr, 2>::type Arg2;
  29
  30         typedef typename lambda::result_of<Arg1, Args>::type T1;
  31         typedef typename lambda::result_of<Arg2, Args>::type T2;
  32
  33         typedef std::pair<T1, T2> type;
  34     };
  35
  36     template<class Context, class Arg1, class Arg2>
  37     static void apply(Context &ctx, const Arg1 &arg1, const Arg2 &arg2)
  38     {
  39         typedef typename lambda::result_of<Arg1, typename Context::args_tuple>::type T1;
  40         typedef typename lambda::result_of<Arg2, typename Context::args_tuple>::type T2;
  41
  42         ctx.stream << "boost_make_pair(";
  43         ctx.stream << type_name<T1>() << ", ";
  44         proto::eval(arg1, ctx);
  45         ctx.stream << ", ";
  46         ctx.stream << type_name<T2>() << ", ";
  47         proto::eval(arg2, ctx);
  48         ctx.stream << ")";
  49     }
  50 };
  51
  52 } // end detail namespace
  53
  54 // make_pair(first, second)
  55 template<class Arg1, class Arg2>
  56 inline typename proto::result_of::make_expr<
  57     proto::tag::function, detail::make_pair_func, const Arg1&, const Arg2&
  58 >::type const
  59 make_pair(const Arg1 &first, const Arg2 &second)
  60 {
  61     return proto::make_expr<proto::tag::function>(
  62         detail::make_pair_func(), ::boost::ref(first), ::boost::ref(second)
  63     );
  64 }
  65
  66 } // end lambda namespace
  67 } // end compute namespace
  68 } // end boost namespace
  69
  70 #endif // BOOST_COMPUTE_LAMBDA_MAKE_PAIR_HPP