1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 // <tuple> 11 12 // constexpr unspecified ignore; 13 14 // UNSUPPORTED: c++98, c++03 15 16 #include <tuple> 17 #include <cassert> 18 19 #include "test_macros.h" 20 test_ignore_constexpr()21constexpr bool test_ignore_constexpr() 22 { 23 #if TEST_STD_VER > 11 24 { // Test that std::ignore provides constexpr converting assignment. 25 auto& res = (std::ignore = 42); 26 assert(&res == &std::ignore); 27 } 28 { // Test that std::ignore provides constexpr copy/move constructors 29 auto copy = std::ignore; 30 auto moved = std::move(copy); 31 ((void)moved); 32 } 33 { // Test that std::ignore provides constexpr copy/move assignment 34 auto copy = std::ignore; 35 copy = std::ignore; 36 auto moved = std::ignore; 37 moved = std::move(copy); 38 } 39 #endif 40 return true; 41 } 42 main()43int main() { 44 { 45 constexpr auto& ignore_v = std::ignore; 46 ((void)ignore_v); 47 } 48 { 49 static_assert(test_ignore_constexpr(), ""); 50 } 51 { 52 LIBCPP_STATIC_ASSERT(std::is_trivial<decltype(std::ignore)>::value, ""); 53 } 54 } 55