1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // UNSUPPORTED: c++03, c++11, c++14
10 // <optional>
11 
12 // constexpr T* optional<T>::operator->();
13 
14 #include <optional>
15 #include <type_traits>
16 #include <cassert>
17 
18 #include "test_macros.h"
19 
20 using std::optional;
21 
22 struct X
23 {
testX24     int test() noexcept {return 3;}
25 };
26 
27 struct Y
28 {
testY29     constexpr int test() {return 3;}
30 };
31 
32 constexpr int
test()33 test()
34 {
35     optional<Y> opt{Y{}};
36     return opt->test();
37 }
38 
main(int,char **)39 int main(int, char**)
40 {
41     {
42         std::optional<X> opt; ((void)opt);
43         ASSERT_SAME_TYPE(decltype(opt.operator->()), X*);
44         // ASSERT_NOT_NOEXCEPT(opt.operator->());
45         // FIXME: This assertion fails with GCC because it can see that
46         // (A) operator->() is constexpr, and
47         // (B) there is no path through the function that throws.
48         // It's arguable if this is the correct behavior for the noexcept
49         // operator.
50         // Regardless this function should still be noexcept(false) because
51         // it has a narrow contract.
52     }
53     {
54         optional<X> opt(X{});
55         assert(opt->test() == 3);
56     }
57     {
58         static_assert(test() == 3, "");
59     }
60 
61     return 0;
62 }
63