ceph/src/boost/libs/variant2/test/variant_visit.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/mp11.hpp>
  15 #include <boost/core/lightweight_test.hpp>
  16 #include <boost/core/lightweight_test_trait.hpp>
  17 #include <boost/config.hpp>
  18 #include <type_traits>
  19 #include <utility>
  20 #include <string>
  21 #include <cstdio>
  22
  23 using namespace boost::variant2;
  24 using boost::mp11::mp_size_t;
  25
  26 struct X
  27 {
  28 };
  29
  30 struct F
  31 {
  32     mp_size_t<1> operator()( X& ) const;
  33     mp_size_t<2> operator()( X const& ) const;
  34     mp_size_t<3> operator()( X&& ) const;
  35     mp_size_t<4> operator()( X const&& ) const;
  36 };
  37
  38 int main()
  39 {
  40     {
  41         BOOST_TEST_EQ( (visit( []{ return 5; } )), 5 );
  42     }
  43
  44     {
  45         variant<int> v( 1 );
  46
  47         BOOST_TEST_EQ( (visit( []( int x ){ return x; }, v )), 1 );
  48
  49         visit( []( int x ){ BOOST_TEST_EQ( x, 1 ); }, v );
  50         visit( []( int x ){ BOOST_TEST_EQ( x, 1 ); }, std::move(v) );
  51     }
  52
  53     {
  54         variant<int> const v( 2 );
  55
  56         BOOST_TEST_EQ( (visit( []( int x ){ return x; }, v )), 2 );
  57
  58         visit( []( int x ){ BOOST_TEST_EQ( x, 2 ); }, v );
  59         visit( []( int x ){ BOOST_TEST_EQ( x, 2 ); }, std::move(v) );
  60     }
  61
  62     {
  63         variant<int const> v( 3 );
  64
  65         BOOST_TEST_EQ( (visit( []( int x ){ return x; }, v )), 3 );
  66
  67         visit( []( int x ){ BOOST_TEST_EQ( x, 3 ); }, v );
  68         visit( []( int x ){ BOOST_TEST_EQ( x, 3 ); }, std::move(v) );
  69     }
  70
  71     {
  72         variant<int const> const v( 4 );
  73
  74         BOOST_TEST_EQ( (visit( []( int x ){ return x; }, v )), 4 );
  75
  76         visit( []( int x ){ BOOST_TEST_EQ( x, 4 ); }, v );
  77         visit( []( int x ){ BOOST_TEST_EQ( x, 4 ); }, std::move(v) );
  78     }
  79
  80     {
  81         variant<int, float> v1( 1 );
  82         variant<int, float> const v2( 3.14f );
  83
  84         BOOST_TEST_EQ( (visit( []( int x1, float x2 ){ return (int)(x1 * 1000) + (int)(x2 * 100); }, v1, v2 )), 1314 );
  85
  86         visit( []( int x1, float x2 ){ BOOST_TEST_EQ( x1, 1 ); BOOST_TEST_EQ( x2, 3.14f ); }, v1, v2 );
  87         visit( []( int x1, float x2 ){ BOOST_TEST_EQ( x1, 1 ); BOOST_TEST_EQ( x2, 3.14f ); }, std::move(v1), std::move(v2) );
  88     }
  89
  90     {
  91         variant<int, float, double> v1( 1 );
  92         variant<int, float, double> const v2( 3.14f );
  93         variant<int, float, double> v3( 6.28 );
  94
  95         BOOST_TEST_EQ( (visit( []( int x1, float x2, double x3 ){ return (int)(x1 * 100) * 1000000 + (int)(x2 * 100) * 1000 + (int)(x3 * 100); }, v1, v2, v3 )), 100314628 );
  96
  97         visit( []( int x1, float x2, double x3 ){ BOOST_TEST_EQ( x1, 1 ); BOOST_TEST_EQ( x2, 3.14f ); BOOST_TEST_EQ( x3, 6.28 ); }, v1, v2, v3 );
  98         visit( []( int x1, float x2, double x3 ){ BOOST_TEST_EQ( x1, 1 ); BOOST_TEST_EQ( x2, 3.14f ); BOOST_TEST_EQ( x3, 6.28 ); }, std::move(v1), std::move(v2), std::move(v3) );
  99     }
 100
 101     {
 102         variant<int, float, double, char> v1( 1 );
 103         variant<int, float, double, char> const v2( 3.14f );
 104         variant<int, float, double, char> v3( 6.28 );
 105         variant<int, float, double, char> const v4( 'A' );
 106
 107         BOOST_TEST_EQ( (visit( []( int x1, float x2, double x3, char x4 ){ return (long long)(x1 * 100) * 100000000 + (long long)(x2 * 100) * 100000 + (long long)(x3 * 10000) + (int)x4; }, v1, v2, v3, v4 )), 10031462800 + 'A' );
 108
 109         visit( []( int x1, float x2, double x3, char x4 ){ BOOST_TEST_EQ( x1, 1 ); BOOST_TEST_EQ( x2, 3.14f ); BOOST_TEST_EQ( x3, 6.28 ); BOOST_TEST_EQ( x4, 'A' ); }, v1, v2, v3, v4 );
 110         visit( []( int x1, float x2, double x3, char x4 ){ BOOST_TEST_EQ( x1, 1 ); BOOST_TEST_EQ( x2, 3.14f ); BOOST_TEST_EQ( x3, 6.28 ); BOOST_TEST_EQ( x4, 'A' ); }, std::move(v1), std::move(v2), std::move(v3), std::move(v4) );
 111     }
 112
 113     {
 114         variant<X> v;
 115         variant<X> const cv;
 116
 117         BOOST_TEST_EQ( decltype(visit(F{}, v))::value, 1 );
 118         BOOST_TEST_EQ( decltype(visit(F{}, cv))::value, 2 );
 119         BOOST_TEST_EQ( decltype(visit(F{}, std::move(v)))::value, 3 );
 120
 121 #if !BOOST_WORKAROUND(BOOST_GCC, < 40900)
 122
 123         // g++ 4.8 doesn't handle const&& particularly well
 124         BOOST_TEST_EQ( decltype(visit(F{}, std::move(cv)))::value, 4 );
 125
 126 #endif
 127     }
 128
 129     return boost::report_errors();
 130 }