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// template <class U> T optional<T>::value_or(U&& v) &&;
13
14#include <experimental/optional>
15#include <type_traits>
16#include <cassert>
17
18#if _LIBCPP_STD_VER > 11
19
20using std::experimental::optional;
21using std::experimental::in_place_t;
22using std::experimental::in_place;
23
24struct Y
25{
26    int i_;
27
28    Y(int i) : i_(i) {}
29};
30
31struct X
32{
33    int i_;
34
35    X(int i) : i_(i) {}
36    X(X&& x) : i_(x.i_) {x.i_ = 0;}
37    X(const Y& y) : i_(y.i_) {}
38    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
43#endif  // _LIBCPP_STD_VER > 11
44
45int main()
46{
47#if _LIBCPP_STD_VER > 11
48    {
49        optional<X> opt(in_place, 2);
50        Y y(3);
51        assert(std::move(opt).value_or(y) == 2);
52        assert(*opt == 0);
53    }
54    {
55        optional<X> opt(in_place, 2);
56        assert(std::move(opt).value_or(Y(3)) == 2);
57        assert(*opt == 0);
58    }
59    {
60        optional<X> opt;
61        Y y(3);
62        assert(std::move(opt).value_or(y) == 3);
63        assert(!opt);
64    }
65    {
66        optional<X> opt;
67        assert(std::move(opt).value_or(Y(3)) == 4);
68        assert(!opt);
69    }
70#endif  // _LIBCPP_STD_VER > 11
71}
72