Howard Hinnant 01afa5c6e4 Implement N3672, optional<T>.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@189772 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-02 20:30:37 +00:00

49 lines
1.3 KiB
C++

//===----------------------------------------------------------------------===//
//
// 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> struct hash<optional<T>>;
#include <optional>
#include <string>
#include <memory>
#include <cassert>
#if _LIBCPP_STD_VER > 11
#endif // _LIBCPP_STD_VER > 11
int main()
{
#if _LIBCPP_STD_VER > 11
{
typedef int T;
std::optional<T> opt;
assert(std::hash<std::optional<T>>{}(opt) == 0);
opt = 2;
assert(std::hash<std::optional<T>>{}(opt) == std::hash<T>{}(*opt));
}
{
typedef std::string T;
std::optional<T> opt;
assert(std::hash<std::optional<T>>{}(opt) == 0);
opt = std::string("123");
assert(std::hash<std::optional<T>>{}(opt) == std::hash<T>{}(*opt));
}
{
typedef std::unique_ptr<int> T;
std::optional<T> opt;
assert(std::hash<std::optional<T>>{}(opt) == 0);
opt = std::unique_ptr<int>(new int(3));
assert(std::hash<std::optional<T>>{}(opt) == std::hash<T>{}(*opt));
}
#endif // _LIBCPP_STD_VER > 11
}