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
|
//===----------------------------------------------------------------------===//
//
// 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 T>
// constexpr
// optional<typename decay<T>::type>
// make_optional(T&& v);
#include <experimental/optional>
#include <string>
#include <memory>
#include <cassert>
int main()
{
#if _LIBCPP_STD_VER > 11
using std::experimental::optional;
using std::experimental::make_optional;
{
optional<int> opt = make_optional(2);
assert(*opt == 2);
}
{
std::string s("123");
optional<std::string> opt = make_optional(s);
assert(*opt == s);
}
{
std::string s("123");
optional<std::string> opt = make_optional(std::move(s));
assert(*opt == "123");
assert(s.empty());
}
{
std::unique_ptr<int> s(new int(3));
optional<std::unique_ptr<int>> opt = make_optional(std::move(s));
assert(**opt == 3);
assert(s == nullptr);
}
#endif // _LIBCPP_STD_VER > 11
}
|
