1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9// UNSUPPORTED: c++03
10// The test requires access control SFINAE.
11
12// <unordered_map>
13
14// Check that std::unordered_map fails to instantiate if the hash function is
15// not copy-constructible. This is mentioned in LWG issue 2436
16
17#include <unordered_map>
18
19template <class T>
20struct Hash {
21 std::size_t operator () (const T& lhs) const { return 0; }
22
23 Hash () {}
24private:
25 Hash (const Hash &); // declared but not defined
26};
27
28
29int main(int, char**) {
30 std::unordered_map<int, int, Hash<int> > m;
31
32 return 0;
33}
34

source code of libcxx/test/std/containers/unord/unord.map/unord.map.cnstr/hash_copy_constructible.compile.fail.cpp