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