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 // <optional> 11 12 // constexpr optional() noexcept; 13 14 #include <experimental/optional> 15 #include <type_traits> 16 #include <cassert> 17 18 #if _LIBCPP_STD_VER > 11 19 20 using std::experimental::optional; 21 22 template <class Opt> 23 void 24 test_constexpr() 25 { 26 static_assert(std::is_nothrow_default_constructible<Opt>::value, ""); 27 constexpr Opt opt; 28 static_assert(static_cast<bool>(opt) == false, ""); 29 30 struct test_constexpr_ctor 31 : public Opt 32 { 33 constexpr test_constexpr_ctor() {} 34 }; 35 36 } 37 38 template <class Opt> 39 void 40 test() 41 { 42 static_assert(std::is_nothrow_default_constructible<Opt>::value, ""); 43 Opt opt; 44 assert(static_cast<bool>(opt) == false); 45 46 struct test_constexpr_ctor 47 : public Opt 48 { 49 constexpr test_constexpr_ctor() {} 50 }; 51 } 52 53 struct X 54 { 55 X(); 56 }; 57 58 #endif // _LIBCPP_STD_VER > 11 59 60 int main() 61 { 62 #if _LIBCPP_STD_VER > 11 63 test_constexpr<optional<int>>(); 64 test_constexpr<optional<int*>>(); 65 test<optional<X>>(); 66 #endif // _LIBCPP_STD_VER > 11 67 } 68
