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// template <class U> constexpr T optional<T>::value_or(U&& v) &&;
13
14#include <optional>
15#include <type_traits>
16#include <cassert>
17
18#include "test_macros.h"
19
20using std::optional;
21using std::in_place_t;
22using std::in_place;
23
24struct Y
25{
26 int i_;
27
28 constexpr Y(int i) : i_(i) {}
29};
30
31struct X
32{
33 int i_;
34
35 constexpr X(int i) : i_(i) {}
36 constexpr X(X&& x) : i_(x.i_) {x.i_ = 0;}
37 constexpr X(const Y& y) : i_(y.i_) {}
38 constexpr X(Y&& y) : i_(y.i_+1) {}
39 friend constexpr bool operator==(const X& x, const X& y)
40 {return x.i_ == y.i_;}
41};
42
43constexpr int test()
44{
45 {
46 optional<X> opt(in_place, 2);
47 Y y(3);
48 assert(std::move(opt).value_or(y) == 2);
49 assert(*opt == 0);
50 }
51 {
52 optional<X> opt(in_place, 2);
53 assert(std::move(opt).value_or(Y(3)) == 2);
54 assert(*opt == 0);
55 }
56 {
57 optional<X> opt;
58 Y y(3);
59 assert(std::move(opt).value_or(y) == 3);
60 assert(!opt);
61 }
62 {
63 optional<X> opt;
64 assert(std::move(opt).value_or(Y(3)) == 4);
65 assert(!opt);
66 }
67 return 0;
68}
69
70int main(int, char**)
71{
72 static_assert(test() == 0);
73
74 return 0;
75}
76

source code of libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_or.pass.cpp