22 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// <regex>10 11// class match_results<BidirectionalIterator, Allocator>12// bool empty() const;13 14// UNSUPPORTED: c++03, c++11, c++14, c++1715 16#include <regex>17 18void f() {19 std::match_results<const char*> c;20 c.empty(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}21}22