variant_size.cpp 4.8 KB

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  1. // Copyright 2017 Peter Dimov.
  2. //
  3. // Distributed under the Boost Software License, Version 1.0.
  4. //
  5. // See accompanying file LICENSE_1_0.txt or copy at
  6. // http://www.boost.org/LICENSE_1_0.txt
  7. #include <boost/variant2/variant.hpp>
  8. #include <boost/mp11.hpp>
  9. #include <boost/core/lightweight_test.hpp>
  10. #include <boost/core/lightweight_test_trait.hpp>
  11. #include <type_traits>
  12. #include <cstddef>
  13. using namespace boost::variant2;
  14. using namespace boost::mp11;
  15. template<class T> using var_size_t = mp_size_t<variant_size<T>::value>;
  16. int main()
  17. {
  18. BOOST_TEST_EQ( (variant_size<variant<>>::value), 0 );
  19. BOOST_TEST_EQ( (variant_size<variant<> const>::value), 0 );
  20. BOOST_TEST_EQ( (variant_size<variant<> volatile>::value), 0 );
  21. BOOST_TEST_EQ( (variant_size<variant<> const volatile>::value), 0 );
  22. BOOST_TEST_EQ( (variant_size<variant<>&>::value), 0 );
  23. BOOST_TEST_EQ( (variant_size<variant<> const&>::value), 0 );
  24. BOOST_TEST_EQ( (variant_size<variant<>&&>::value), 0 );
  25. BOOST_TEST_EQ( (variant_size<variant<> const&&>::value), 0 );
  26. BOOST_TEST_EQ( (variant_size<variant<void>>::value), 1 );
  27. BOOST_TEST_EQ( (variant_size<variant<void> const>::value), 1 );
  28. BOOST_TEST_EQ( (variant_size<variant<void> volatile>::value), 1 );
  29. BOOST_TEST_EQ( (variant_size<variant<void> const volatile>::value), 1 );
  30. BOOST_TEST_EQ( (variant_size<variant<void>&>::value), 1 );
  31. BOOST_TEST_EQ( (variant_size<variant<void> const&>::value), 1 );
  32. BOOST_TEST_EQ( (variant_size<variant<void>&&>::value), 1 );
  33. BOOST_TEST_EQ( (variant_size<variant<void> const&&>::value), 1 );
  34. BOOST_TEST_EQ( (variant_size<variant<void, void>>::value), 2 );
  35. BOOST_TEST_EQ( (variant_size<variant<void, void> const>::value), 2 );
  36. BOOST_TEST_EQ( (variant_size<variant<void, void> volatile>::value), 2 );
  37. BOOST_TEST_EQ( (variant_size<variant<void, void> const volatile>::value), 2 );
  38. BOOST_TEST_EQ( (variant_size<variant<void, void>&>::value), 2 );
  39. BOOST_TEST_EQ( (variant_size<variant<void, void> const&>::value), 2 );
  40. BOOST_TEST_EQ( (variant_size<variant<void, void>&&>::value), 2 );
  41. BOOST_TEST_EQ( (variant_size<variant<void, void> const&&>::value), 2 );
  42. BOOST_TEST_EQ( (variant_size<variant<void, void, void>>::value), 3 );
  43. BOOST_TEST_EQ( (variant_size<variant<void, void, void> const>::value), 3 );
  44. BOOST_TEST_EQ( (variant_size<variant<void, void, void> volatile>::value), 3 );
  45. BOOST_TEST_EQ( (variant_size<variant<void, void, void> const volatile>::value), 3 );
  46. BOOST_TEST_EQ( (variant_size<variant<void, void, void>&>::value), 3 );
  47. BOOST_TEST_EQ( (variant_size<variant<void, void, void> const&>::value), 3 );
  48. BOOST_TEST_EQ( (variant_size<variant<void, void, void>&&>::value), 3 );
  49. BOOST_TEST_EQ( (variant_size<variant<void, void, void> const&&>::value), 3 );
  50. BOOST_TEST_EQ( (variant_size<variant<void, void, void, void>>::value), 4 );
  51. BOOST_TEST_EQ( (variant_size<variant<void, void, void, void> const>::value), 4 );
  52. BOOST_TEST_EQ( (variant_size<variant<void, void, void, void> volatile>::value), 4 );
  53. BOOST_TEST_EQ( (variant_size<variant<void, void, void, void> const volatile>::value), 4 );
  54. BOOST_TEST_EQ( (variant_size<variant<void, void, void, void>&>::value), 4 );
  55. BOOST_TEST_EQ( (variant_size<variant<void, void, void, void> const&>::value), 4 );
  56. BOOST_TEST_EQ( (variant_size<variant<void, void, void, void>&&>::value), 4 );
  57. BOOST_TEST_EQ( (variant_size<variant<void, void, void, void> const&&>::value), 4 );
  58. variant_size<void>();
  59. variant_size<void const>();
  60. variant_size<void volatile>();
  61. variant_size<void const volatile>();
  62. variant_size<int&>();
  63. variant_size<int const&>();
  64. variant_size<int&&>();
  65. variant_size<int const&&>();
  66. BOOST_TEST_TRAIT_FALSE((mp_valid<var_size_t, void>));
  67. BOOST_TEST_TRAIT_FALSE((mp_valid<var_size_t, void const>));
  68. BOOST_TEST_TRAIT_FALSE((mp_valid<var_size_t, void volatile>));
  69. BOOST_TEST_TRAIT_FALSE((mp_valid<var_size_t, void const volatile>));
  70. BOOST_TEST_TRAIT_FALSE((mp_valid<var_size_t, int&>));
  71. BOOST_TEST_TRAIT_FALSE((mp_valid<var_size_t, int const&>));
  72. BOOST_TEST_TRAIT_FALSE((mp_valid<var_size_t, int&&>));
  73. BOOST_TEST_TRAIT_FALSE((mp_valid<var_size_t, int const&&>));
  74. BOOST_TEST_TRAIT_TRUE((mp_valid<var_size_t, variant<>>));
  75. BOOST_TEST_TRAIT_TRUE((mp_valid<var_size_t, variant<> const>));
  76. BOOST_TEST_TRAIT_TRUE((mp_valid<var_size_t, variant<> volatile>));
  77. BOOST_TEST_TRAIT_TRUE((mp_valid<var_size_t, variant<> const volatile>));
  78. BOOST_TEST_TRAIT_TRUE((mp_valid<var_size_t, variant<>&>));
  79. BOOST_TEST_TRAIT_TRUE((mp_valid<var_size_t, variant<> const&>));
  80. BOOST_TEST_TRAIT_TRUE((mp_valid<var_size_t, variant<>&&>));
  81. BOOST_TEST_TRAIT_TRUE((mp_valid<var_size_t, variant<> const&&>));
  82. return boost::report_errors();
  83. }