ceph/src/boost/libs/variant2/test/variant_value_assign_cx.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 #include <boost/variant2/variant.hpp>
  10
  11 using namespace boost::variant2;
  12
  13 struct X
  14 {
  15     int v;
  16     X() = default;
  17     constexpr X( int v ): v( v ) {}
  18     constexpr operator int() const { return v; }
  19 };
  20
  21 struct Y
  22 {
  23     int v;
  24     constexpr Y(): v() {}
  25     constexpr Y( int v ): v( v ) {}
  26     constexpr operator int() const { return v; }
  27 };
  28
  29 enum E
  30 {
  31     v
  32 };
  33
  34 #define STATIC_ASSERT(...) static_assert(__VA_ARGS__, #__VA_ARGS__)
  35
  36 template<class V, class T, class A> constexpr A test( A const& a )
  37 {
  38     V v;
  39
  40     v = a;
  41
  42     return get<T>(v);
  43 }
  44
  45 int main()
  46 {
  47     {
  48         constexpr auto w = test<variant<int>, int>( 1 );
  49         STATIC_ASSERT( w == 1 );
  50     }
  51
  52     {
  53         constexpr auto w = test<variant<X>, X>( 1 );
  54         STATIC_ASSERT( w == 1 );
  55     }
  56
  57 #if defined( BOOST_LIBSTDCXX_VERSION ) && BOOST_LIBSTDCXX_VERSION < 50000
  58 #else
  59
  60     {
  61         constexpr auto w = test<variant<Y>, Y>( 1 );
  62         STATIC_ASSERT( w == 1 );
  63     }
  64
  65 #endif
  66
  67     {
  68         constexpr auto w = test<variant<int, float>, int>( 1 );
  69         STATIC_ASSERT( w == 1 );
  70     }
  71
  72     {
  73         constexpr auto w = test<variant<int, float>, float>( 3.0f );
  74         STATIC_ASSERT( w == 3.0f );
  75     }
  76
  77     {
  78         constexpr auto w = test<variant<int, int, float>, float>( 3.0f );
  79         STATIC_ASSERT( w == 3.0f );
  80     }
  81
  82     {
  83         constexpr auto w = test<variant<E, E, X>, X>( 1 );
  84         STATIC_ASSERT( w == 1 );
  85     }
  86
  87     {
  88         constexpr auto w = test<variant<int, int, float, float, X>, X>( X(1) );
  89         STATIC_ASSERT( w == 1 );
  90     }
  91
  92 #if defined( BOOST_LIBSTDCXX_VERSION ) && BOOST_LIBSTDCXX_VERSION < 50000
  93 #else
  94
  95     {
  96         constexpr auto w = test<variant<E, E, Y>, Y>( 1 );
  97         STATIC_ASSERT( w == 1 );
  98     }
  99
 100     {
 101         constexpr auto w = test<variant<int, int, float, float, Y>, Y>( Y(1) );
 102         STATIC_ASSERT( w == 1 );
 103     }
 104
 105 #endif
 106 }