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 17 #include <vector> 18 #include <iterator> 19 20 #include "test_macros.h" 21 22 int main(int, char**) 23 { 24 std::vector<int> c; 25 std::empty(c); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} 26 27 return 0; 28 } 29