1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 // <iterator> 11 12 // <iterator> 13 // template <class C> constexpr auto empty(const C& c) -> decltype(c.empty()); 14 15 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17 16 // REQUIRES: verify-support 17 18 #include <vector> 19 #include <iterator> 20 21 #include "test_macros.h" 22 23 int main(int, char**) 24 { 25 std::vector<int> c; 26 std::empty(c); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 27 28 return 0; 29 } 30