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) const&;
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 Y
23 {
24 int i_;
25
YY26 constexpr Y(int i) : i_(i) {}
27 };
28
29 struct X
30 {
31 int i_;
32
XX33 constexpr X(int i) : i_(i) {}
XX34 constexpr X(const Y& y) : i_(y.i_) {}
XX35 constexpr X(Y&& y) : i_(y.i_+1) {}
operator ==(const X & x,const X & y)36 friend constexpr bool operator==(const X& x, const X& y)
37 {return x.i_ == y.i_;}
38 };
39
main(int,char **)40 int main(int, char**)
41 {
42 {
43 constexpr optional<X> opt(2);
44 constexpr Y y(3);
45 static_assert(opt.value_or(y) == 2, "");
46 }
47 {
48 constexpr optional<X> opt(2);
49 static_assert(opt.value_or(Y(3)) == 2, "");
50 }
51 {
52 constexpr optional<X> opt;
53 constexpr Y y(3);
54 static_assert(opt.value_or(y) == 3, "");
55 }
56 {
57 constexpr optional<X> opt;
58 static_assert(opt.value_or(Y(3)) == 4, "");
59 }
60 {
61 const optional<X> opt(2);
62 const Y y(3);
63 assert(opt.value_or(y) == 2);
64 }
65 {
66 const optional<X> opt(2);
67 assert(opt.value_or(Y(3)) == 2);
68 }
69 {
70 const optional<X> opt;
71 const Y y(3);
72 assert(opt.value_or(y) == 3);
73 }
74 {
75 const optional<X> opt;
76 assert(opt.value_or(Y(3)) == 4);
77 }
78
79 return 0;
80 }
81