ceph/src/boost/libs/variant2/test/variant_visit_r.cpp

   1
   2 // Copyright 2017 Peter Dimov.
   3 //
   4 // Distributed under the Boost Software License, Version 1.0.
   5 //
   6 // See accompanying file LICENSE_1_0.txt or copy at
   7 // http://www.boost.org/LICENSE_1_0.txt
   8
   9 #if defined(_MSC_VER)
  10 # pragma warning( disable: 4244 ) // conversion from float to int, possible loss of data
  11 #endif
  12
  13 #include <boost/variant2/variant.hpp>
  14 #include <boost/core/lightweight_test.hpp>
  15
  16 using namespace boost::variant2;
  17
  18 struct F1
  19 {
  20     template<class T1> T1 operator()( T1 t1 ) const
  21     {
  22         return t1;
  23     }
  24 };
  25
  26 struct F2
  27 {
  28     template<class T1, class T2> auto operator()( T1 t1, T2 t2 ) const -> decltype( t1 + t2 )
  29     {
  30         return t1 + t2;
  31     }
  32 };
  33
  34 struct F3
  35 {
  36     template<class T1, class T2, class T3> auto operator()( T1 t1, T2 t2, T3 t3 ) const -> decltype( t1 + t2 + t3 )
  37     {
  38         return t1 + t2 + t3;
  39     }
  40 };
  41
  42 struct F4
  43 {
  44     template<class T1, class T2, class T3, class T4> auto operator()( T1 t1, T2 t2, T3 t3, T4 t4 ) const -> decltype( t1 + t2 + t3 + t4 )
  45     {
  46         return t1 + t2 + t3 + t4;
  47     }
  48 };
  49
  50 int main()
  51 {
  52     {
  53         BOOST_TEST_EQ( (visit<int>( []{ return 3.14f; } )), 3 );
  54     }
  55
  56     {
  57         variant<int, float> v( 1 );
  58
  59         BOOST_TEST_EQ( visit<int>( F1(), v ), 1 );
  60         BOOST_TEST_EQ( visit<float>( F1(), v ), 1.0f );
  61     }
  62
  63     {
  64         variant<int, float> const v( 3.14f );
  65
  66         BOOST_TEST_EQ( visit<int>( F1(), v ), 3 );
  67         BOOST_TEST_EQ( visit<float>( F1(), v ), 3.14f );
  68     }
  69
  70     {
  71         variant<int, float> v1( 1 );
  72         variant<int, float> const v2( 3.14f );
  73
  74         BOOST_TEST_EQ( visit<int>( F2(), v1, v2 ), 4 );
  75         BOOST_TEST_EQ( visit<float>( F2(), v1, v2 ), 1 + 3.14f );
  76     }
  77
  78     {
  79         variant<int, float, double> v1( 1 );
  80         variant<int, float, double> const v2( 3.14f );
  81         variant<int, float, double> v3( 6.28 );
  82
  83         BOOST_TEST_EQ( visit<int>( F3(), v1, v2, v3 ), 10 );
  84         BOOST_TEST_EQ( visit<float>( F3(), v1, v2, v3 ), static_cast<float>( 1 + 3.14f + 6.28 ) );
  85     }
  86
  87     {
  88         variant<int, float, double, char> v1( 1 );
  89         variant<int, float, double, char> const v2( 3.14f );
  90         variant<int, float, double, char> v3( 6.28 );
  91         variant<int, float, double, char> const v4( 'A' );
  92
  93         BOOST_TEST_EQ( visit<int>( F4(), v1, v2, v3, v4 ), 10 + 'A' );
  94         BOOST_TEST_EQ( visit<float>( F4(), v1, v2, v3, v4 ), static_cast<float>( 1 + 3.14f + 6.28 + 'A' ) );
  95     }
  96
  97     return boost::report_errors();
  98 }