llvm-project/libcxx/test/std/utilities/optional/optional.hash/hash.pass.cpp

49 lines
1.4 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.
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++98, c++03, c++11, c++14
// <optional>
// template <class T> struct hash<optional<T>>;
#include <optional>
#include <string>
#include <memory>
#include <cassert>
int main()
{
using std::optional;
const std::size_t nullopt_hash =
std::hash<optional<double>>{}(optional<double>{});
{
typedef int T;
optional<T> opt;
assert(std::hash<optional<T>>{}(opt) == nullopt_hash);
opt = 2;
assert(std::hash<optional<T>>{}(opt) == std::hash<T>{}(*opt));
}
{
typedef std::string T;
optional<T> opt;
assert(std::hash<optional<T>>{}(opt) == nullopt_hash);
opt = std::string("123");
assert(std::hash<optional<T>>{}(opt) == std::hash<T>{}(*opt));
}
{
typedef std::unique_ptr<int> T;
optional<T> opt;
assert(std::hash<optional<T>>{}(opt) == nullopt_hash);
opt = std::unique_ptr<int>(new int(3));
assert(std::hash<optional<T>>{}(opt) == std::hash<T>{}(*opt));
}
}