23 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9// <string>10 11// class deque12 13// bool empty() const noexcept; // constexpr since C++2014 15// UNSUPPORTED: c++03, c++11, c++14, c++1716 17#include <string>18 19void f() {20 std::string c;21 c.empty(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}22}23