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// UNSUPPORTED: c++03, c++11, c++14, c++17
9
10// <span>
11
12// [[nodiscard]] constexpr bool empty() const noexcept;
13
14#include <span>
15
16void test() {
17 std::span<int> s1;
18 s1.empty(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
19
20 int arr[] = {1, 2, 3};
21 std::span<int, 3> s2{arr};
22 s2.empty(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
23}
24

source code of libcxx/test/std/containers/views/views.span/span.obs/empty.nodiscard.verify.cpp