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 11 // <optional> 12 13 // T& optional<T>::value(); 14 15 #include <experimental/optional> 16 #include <type_traits> 17 #include <cassert> 18 19 #include "test_macros.h" 20 21 using std::experimental::optional; 22 using std::experimental::bad_optional_access; 23 24 struct X 25 { 26 X() = default; 27 X(const X&) = delete; testX28 constexpr int test() const {return 3;} testX29 int test() {return 4;} 30 }; 31 main()32int main() 33 { 34 { 35 optional<X> opt; 36 opt.emplace(); 37 assert(opt.value().test() == 4); 38 } 39 #ifndef TEST_HAS_NO_EXCEPTIONS 40 { 41 optional<X> opt; 42 try 43 { 44 opt.value(); 45 assert(false); 46 } 47 catch (const bad_optional_access&) 48 { 49 } 50 } 51 #endif 52 } 53