75 struct Y2  struct
81     Y2() noexcept: v(0) { ++instances; }  in Y2()  argument
82     explicit Y2(int v) noexcept: v(v) { ++instances; }  in Y2()  function
83     Y2(Y2 const& r) noexcept: v(r.v) { ++instances; }  in Y2()  argument
84     Y2(Y2&& r) noexcept: v(r.v) { ++instances; }  in Y2()  argument
86     ~Y2() noexcept { --instances; }  in ~Y2()  argument
88     Y2& operator=( Y2 const& r ) noexcept { v = r.v; return *this; }  in operator =()  argument
89     Y2& operator=( Y2&& r ) noexcept { v = r.v; return *this; }  in operator =()  argument
92 int Y2::instances = 0;
117     BOOST_TEST_EQ( Y2::instances, 0 );  in main()
120         variant<Y1, Y2> v;  in main()
123         BOOST_TEST_EQ( Y2::instances, 0 );  in main()
126             variant<Y1, Y2> v2;  in main()
128             BOOST_TEST_EQ( Y2::instances, 0 );  in main()
132             BOOST_TEST_EQ( Y2::instances, 0 );  in main()
134             v2 = Y2{1};  in main()
136             BOOST_TEST_EQ( Y2::instances, 1 );  in main()
140             BOOST_TEST_EQ( Y2::instances, 2 );  in main()
144         BOOST_TEST_EQ( Y2::instances, 1 );  in main()
149         BOOST_TEST_EQ( Y2::instances, 0 );  in main()
151         v.emplace<Y2>();  in main()
154         BOOST_TEST_EQ( Y2::instances, 1 );  in main()
158     BOOST_TEST_EQ( Y2::instances, 0 );  in main()