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 // UNSUPPORTED: c++98, c++03, c++11, c++14 11 // <optional> 12 13 // constexpr T& optional<T>::value() &; 14 15 #include <optional> 16 #include <type_traits> 17 #include <cassert> 18 19 #include "test_macros.h" 20 21 using std::optional; 22 using std::bad_optional_access; 23 24 struct X 25 { 26 X() = default; 27 X(const X&) = delete; 28 constexpr int test() const & {return 3;} 29 int test() & {return 4;} 30 constexpr int test() const && {return 5;} 31 int test() && {return 6;} 32 }; 33 34 struct Y 35 { 36 constexpr int test() & {return 7;} 37 }; 38 39 constexpr int 40 test() 41 { 42 optional<Y> opt{Y{}}; 43 return opt.value().test(); 44 } 45 46 47 int main() 48 { 49 { 50 optional<X> opt; ((void)opt); 51 ASSERT_NOT_NOEXCEPT(opt.value()); 52 ASSERT_SAME_TYPE(decltype(opt.value()), X&); 53 } 54 { 55 optional<X> opt; 56 opt.emplace(); 57 assert(opt.value().test() == 4); 58 } 59 #ifndef TEST_HAS_NO_EXCEPTIONS 60 { 61 optional<X> opt; 62 try 63 { 64 opt.value(); 65 assert(false); 66 } 67 catch (const bad_optional_access&) 68 { 69 } 70 } 71 #endif 72 static_assert(test() == 7, ""); 73 } 74
