1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <optional>
// template <class U> optional<T>& operator=(U&& v);
#include <experimental/optional>
#include <type_traits>
#include <cassert>
#include <memory>
#if _LIBCPP_STD_VER > 11
using std::experimental::optional;
struct X
{
};
#endif // _LIBCPP_STD_VER > 11
int main()
{
#if _LIBCPP_STD_VER > 11
static_assert(std::is_assignable<optional<int>, int>::value, "");
static_assert(std::is_assignable<optional<int>, int&>::value, "");
static_assert(std::is_assignable<optional<int>&, int>::value, "");
static_assert(std::is_assignable<optional<int>&, int&>::value, "");
static_assert(std::is_assignable<optional<int>&, const int&>::value, "");
static_assert(!std::is_assignable<const optional<int>&, const int&>::value, "");
static_assert(!std::is_assignable<optional<int>, X>::value, "");
{
optional<int> opt;
opt = 1;
assert(static_cast<bool>(opt) == true);
assert(*opt == 1);
}
{
optional<int> opt;
const int i = 2;
opt = i;
assert(static_cast<bool>(opt) == true);
assert(*opt == i);
}
{
optional<int> opt(3);
const int i = 2;
opt = i;
assert(static_cast<bool>(opt) == true);
assert(*opt == i);
}
{
optional<std::unique_ptr<int>> opt;
opt = std::unique_ptr<int>(new int(3));
assert(static_cast<bool>(opt) == true);
assert(**opt == 3);
}
{
optional<std::unique_ptr<int>> opt(std::unique_ptr<int>(new int(2)));
opt = std::unique_ptr<int>(new int(3));
assert(static_cast<bool>(opt) == true);
assert(**opt == 3);
}
#endif // _LIBCPP_STD_VER > 11
}
|
