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>::operator*() const &&; 14 15 #ifdef _LIBCPP_DEBUG 16 #define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : std::exit(0)) 17 #endif 18 19 #include <optional> 20 #include <type_traits> 21 #include <cassert> 22 23 #include "test_macros.h" 24 25 using std::optional; 26 27 struct X 28 { testX29 constexpr int test() const& {return 3;} testX30 int test() & {return 4;} testX31 constexpr int test() const&& {return 5;} testX32 int test() && {return 6;} 33 }; 34 35 struct Y 36 { testY37 int test() const && {return 2;} 38 }; 39 main()40int main() 41 { 42 { 43 const optional<X> opt; ((void)opt); 44 ASSERT_SAME_TYPE(decltype(*std::move(opt)), X const &&); 45 // ASSERT_NOT_NOEXCEPT(*std::move(opt)); 46 // FIXME: This assertion fails with GCC because it can see that 47 // (A) operator*() is constexpr, and 48 // (B) there is no path through the function that throws. 49 // It's arguable if this is the correct behavior for the noexcept 50 // operator. 51 // Regardless this function should still be noexcept(false) because 52 // it has a narrow contract. 53 } 54 { 55 constexpr optional<X> opt(X{}); 56 static_assert((*std::move(opt)).test() == 5, ""); 57 } 58 { 59 constexpr optional<Y> opt(Y{}); 60 assert((*std::move(opt)).test() == 2); 61 } 62 #ifdef _LIBCPP_DEBUG 63 { 64 optional<X> opt; 65 assert((*std::move(opt)).test() == 5); 66 assert(false); 67 } 68 #endif // _LIBCPP_DEBUG 69 } 70