variant_destroy.cpp 4.6 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/core/lightweight_test.hpp>
  9. #include <boost/core/lightweight_test_trait.hpp>
  10. #include <type_traits>
  11. #include <utility>
  12. #include <string>
  13. using namespace boost::variant2;
  14. struct X1
  15. {
  16. static int instances;
  17. int v;
  18. X1(): v(0) { ++instances; }
  19. explicit X1(int v): v(v) { ++instances; }
  20. X1(X1 const& r): v(r.v) { ++instances; }
  21. X1(X1&& r): v(r.v) { ++instances; }
  22. ~X1() noexcept { --instances; }
  23. X1& operator=( X1 const& r ) { v = r.v; return *this; }
  24. X1& operator=( X1&& r ) { v = r.v; return *this; }
  25. };
  26. int X1::instances = 0;
  27. struct X2
  28. {
  29. static int instances;
  30. int v;
  31. X2(): v(0) { ++instances; }
  32. explicit X2(int v): v(v) { ++instances; }
  33. X2(X2 const& r): v(r.v) { ++instances; }
  34. X2(X2&& r): v(r.v) { ++instances; }
  35. ~X2() noexcept { --instances; }
  36. X2& operator=( X2 const& r ) { v = r.v; return *this; }
  37. X2& operator=( X2&& r ) { v = r.v; return *this; }
  38. };
  39. int X2::instances = 0;
  40. struct Y1
  41. {
  42. static int instances;
  43. int v;
  44. Y1() noexcept: v(0) { ++instances; }
  45. explicit Y1(int v) noexcept: v(v) { ++instances; }
  46. Y1(Y1 const& r) noexcept: v(r.v) { ++instances; }
  47. Y1(Y1&& r) noexcept: v(r.v) { ++instances; }
  48. ~Y1() noexcept { --instances; }
  49. Y1& operator=( Y1 const& r ) noexcept { v = r.v; return *this; }
  50. Y1& operator=( Y1&& r ) noexcept { v = r.v; return *this; }
  51. };
  52. int Y1::instances = 0;
  53. struct Y2
  54. {
  55. static int instances;
  56. int v;
  57. Y2() noexcept: v(0) { ++instances; }
  58. explicit Y2(int v) noexcept: v(v) { ++instances; }
  59. Y2(Y2 const& r) noexcept: v(r.v) { ++instances; }
  60. Y2(Y2&& r) noexcept: v(r.v) { ++instances; }
  61. ~Y2() noexcept { --instances; }
  62. Y2& operator=( Y2 const& r ) noexcept { v = r.v; return *this; }
  63. Y2& operator=( Y2&& r ) noexcept { v = r.v; return *this; }
  64. };
  65. int Y2::instances = 0;
  66. int main()
  67. {
  68. BOOST_TEST_EQ( Y1::instances, 0 );
  69. {
  70. variant<Y1> v;
  71. BOOST_TEST_EQ( Y1::instances, 1 );
  72. {
  73. variant<Y1> v2;
  74. BOOST_TEST_EQ( Y1::instances, 2 );
  75. v = v2;
  76. BOOST_TEST_EQ( Y1::instances, 2 );
  77. }
  78. BOOST_TEST_EQ( Y1::instances, 1 );
  79. v = Y1{1};
  80. BOOST_TEST_EQ( Y1::instances, 1 );
  81. }
  82. BOOST_TEST_EQ( Y1::instances, 0 );
  83. BOOST_TEST_EQ( Y2::instances, 0 );
  84. {
  85. variant<Y1, Y2> v;
  86. BOOST_TEST_EQ( Y1::instances, 1 );
  87. BOOST_TEST_EQ( Y2::instances, 0 );
  88. {
  89. variant<Y1, Y2> v2;
  90. BOOST_TEST_EQ( Y1::instances, 2 );
  91. BOOST_TEST_EQ( Y2::instances, 0 );
  92. v = v2;
  93. BOOST_TEST_EQ( Y1::instances, 2 );
  94. BOOST_TEST_EQ( Y2::instances, 0 );
  95. v2 = Y2{1};
  96. BOOST_TEST_EQ( Y1::instances, 1 );
  97. BOOST_TEST_EQ( Y2::instances, 1 );
  98. v = v2;
  99. BOOST_TEST_EQ( Y1::instances, 0 );
  100. BOOST_TEST_EQ( Y2::instances, 2 );
  101. }
  102. BOOST_TEST_EQ( Y1::instances, 0 );
  103. BOOST_TEST_EQ( Y2::instances, 1 );
  104. v.emplace<0>();
  105. BOOST_TEST_EQ( Y1::instances, 1 );
  106. BOOST_TEST_EQ( Y2::instances, 0 );
  107. v.emplace<Y2>();
  108. BOOST_TEST_EQ( Y1::instances, 0 );
  109. BOOST_TEST_EQ( Y2::instances, 1 );
  110. }
  111. BOOST_TEST_EQ( Y1::instances, 0 );
  112. BOOST_TEST_EQ( Y2::instances, 0 );
  113. BOOST_TEST_EQ( X1::instances, 0 );
  114. BOOST_TEST_EQ( X2::instances, 0 );
  115. {
  116. variant<X1, X2> v;
  117. BOOST_TEST_EQ( X1::instances, 1 );
  118. BOOST_TEST_EQ( X2::instances, 0 );
  119. {
  120. variant<X1, X2> v2;
  121. BOOST_TEST_EQ( X1::instances, 2 );
  122. BOOST_TEST_EQ( X2::instances, 0 );
  123. v = v2;
  124. BOOST_TEST_EQ( X1::instances, 2 );
  125. BOOST_TEST_EQ( X2::instances, 0 );
  126. v2 = X2{1};
  127. BOOST_TEST_EQ( X1::instances, 1 );
  128. BOOST_TEST_EQ( X2::instances, 1 );
  129. v = v2;
  130. BOOST_TEST_EQ( X1::instances, 0 );
  131. BOOST_TEST_EQ( X2::instances, 2 );
  132. }
  133. BOOST_TEST_EQ( X1::instances, 0 );
  134. BOOST_TEST_EQ( X2::instances, 1 );
  135. v.emplace<0>();
  136. BOOST_TEST_EQ( X1::instances, 1 );
  137. BOOST_TEST_EQ( X2::instances, 0 );
  138. v.emplace<X2>();
  139. BOOST_TEST_EQ( X1::instances, 0 );
  140. BOOST_TEST_EQ( X2::instances, 1 );
  141. }
  142. BOOST_TEST_EQ( X1::instances, 0 );
  143. BOOST_TEST_EQ( X2::instances, 0 );
  144. return boost::report_errors();
  145. }