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-exception
6//
7//===----------------------------------------------------------------------===//
8
9// <iterator>
10
11// <iterator>
12// template <class C> constexpr auto empty(const C& c) -> decltype(c.empty());
13
14// UNSUPPORTED: c++03, c++11, c++14, c++17
15
16#include <vector>
17#include <iterator>
18
19void f() {
20 std::vector<int> c;
21 std::empty(cont: c); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
22}
23

source code of libcxx/test/std/iterators/iterator.container/empty.container.verify.cpp