blob: c0cad32da198b6c706762f52d6be1a1a7134d317 [file] [log] [blame]
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: no-threads
// [[nodiscard]] isn't supported in C++03 (not even as an extension)
// UNSUPPORTED: c++03
// <mutex>
// template <class Mutex> class lock_guard;
// [[nodiscard]] explicit lock_guard(mutex_type& m);
// [[nodiscard]] lock_guard(mutex_type& m, adopt_lock_t);
// Test that we properly apply [[nodiscard]] to lock_guard's constructors,
// which is a libc++ extension.
#include <mutex>
int main(int, char**) {
std::mutex m;
std::lock_guard<std::mutex>{m}; // expected-warning {{ignoring temporary created by a constructor declared with 'nodiscard' attribute}}
std::lock_guard<std::mutex>{m, std::adopt_lock}; // expected-warning {{ignoring temporary created by a constructor declared with 'nodiscard' attribute}}
return 0;
}