ceph/src/boost/libs/phoenix/test/function/lazy_make_pair_tests.cpp

   1 ////////////////////////////////////////////////////////////////////////////
   2 // lazy_make_pair_tests.cpp
   3 //
   4 // lazy make_pair test solving the optimizer problem.
   5 //
   6 ////////////////////////////////////////////////////////////////////////////
   7 /*=============================================================================
   8     Copyright (c) 2001-2007 Joel de Guzman
   9     Copyright (c) 2015 John Fletcher
  10
  11     Distributed under the Boost Software License, Version 1.0. (See accompanying
  12     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  13 ==============================================================================*/
  14
  15 #include <boost/phoenix/core/limits.hpp>
  16
  17 #include <boost/detail/lightweight_test.hpp>
  18 #include <boost/phoenix/core.hpp>
  19 #include <boost/phoenix/function.hpp>
  20
  21 namespace boost {
  22
  23   namespace phoenix {
  24
  25 #ifdef BOOST_RESULT_OF_USE_TR1
  26
  27     namespace result_of {
  28
  29       template <
  30           typename Arg1
  31         , typename Arg2
  32       >
  33       class make_pair
  34       {
  35       public:
  36         typedef typename boost::remove_reference<Arg1>::type Arg1Type;
  37         typedef typename boost::remove_reference<Arg2>::type Arg2Type;
  38         typedef std::pair<Arg1Type,Arg2Type> type;
  39       };
  40     }
  41 #endif
  42
  43   namespace impl
  44   {
  45
  46     struct make_pair {
  47
  48
  49 #ifdef BOOST_RESULT_OF_USE_TR1
  50        template <typename Sig>
  51        struct result;
  52        // This fails with -O2 unless refs are removed from A1 and A2.
  53        template <typename This, typename A0, typename A1>
  54        struct result<This(A0, A1)>
  55        {
  56          typedef typename result_of::make_pair<A0,A1>::type type;
  57        };
  58 #else
  59        template <typename Sig>
  60        struct result;
  61
  62        template <typename This, typename A0, typename A1>
  63        struct result<This(A0, A1)>
  64          : boost::remove_reference<std::pair<A0, A1> >
  65        {};
  66
  67 #endif
  68
  69
  70        template <typename A0, typename A1>
  71 #ifdef BOOST_RESULT_OF_USE_TR1
  72        typename result<make_pair(A0,A1)>::type
  73 #else
  74        std::pair<A0, A1>
  75 #endif
  76        operator()(A0 const & a0, A1 const & a1) const
  77        {
  78           return std::make_pair(a0,a1);
  79        }
  80
  81     };
  82   }
  83
  84 BOOST_PHOENIX_ADAPT_CALLABLE(make_pair, impl::make_pair, 2)
  85
  86   }
  87
  88 }
  89
  90 int main()
  91 {
  92     namespace phx = boost::phoenix;
  93     using boost::phoenix::arg_names::arg1;
  94     using boost::phoenix::arg_names::arg2;
  95     int a = 99; int b = 256;
  96
  97     std::pair<int,int> ab1 = phx::make_pair(a,b)();
  98     //std::cout << ab1.first << "," << ab1.second << std::endl;
  99     BOOST_TEST(ab1.first == 99 && ab1.second == 256);
 100     std::pair<int,int> ab2 = phx::make_pair(arg1,b)(a);
 101     //std::cout << ab2.first << "," << ab2.second << std::endl;
 102     BOOST_TEST(ab2.first == 99 && ab2.second == 256);
 103     std::pair<int,int> ab3 = phx::make_pair(arg1,arg2)(a,b);
 104     //std::cout << ab3.first << "," << ab3.second << std::endl;
 105     BOOST_TEST(ab3.first == 99 && ab3.second == 256);
 106
 107
 108     return boost::report_errors();
 109 }