29     if (12 != std::exchange(v,23) || v != 23)  in test_constexpr()
32     if (23 != std::exchange(v,static_cast<short>(67)) || v != 67)  in test_constexpr()
35     if (67 != std::exchange<int, short>(v, {}) || v != 0)  in test_constexpr()
53     ASSERT_NOEXCEPT(std::exchange(x, 42));  in test_noexcept()
57     ASSERT_NOEXCEPT(std::exchange(x, std::move(x)));  in test_noexcept()
58     ASSERT_NOT_NOEXCEPT(std::exchange(x, x)); // copy-assignment is not noexcept  in test_noexcept()
62     ASSERT_NOT_NOEXCEPT(std::exchange(x, std::move(x)));  in test_noexcept()
66     ASSERT_NOT_NOEXCEPT(std::exchange(x, std::move(x)));  in test_noexcept()
76     assert ( std::exchange ( v, 23 ) == 12 );  in main()
78     assert ( std::exchange ( v, static_cast<short>(67) ) == 23 );  in main()
81     assert ((std::exchange<int, short> ( v, {} )) == 67 );  in main()
88     assert ( !std::exchange ( b, true ));  in main()
96     assert ( std::exchange ( s3, s2 ) == s1 );  in main()
98     assert ( std::exchange ( s3, "Hi Mom!" ) == s2 );  in main()
102     assert ( std::exchange ( s3, {} ) == s2 );  in main()
106     assert ( std::exchange ( s3, "" ) == s2 );  in main()