1 // -*- C++ -*-
2 //===----------------------------------------------------------------------===//
3 //
4 // The LLVM Compiler Infrastructure
5 //
6 // This file is dual licensed under the MIT and the University of Illinois Open
7 // Source Licenses. See LICENSE.TXT for details.
8 //
9 //===----------------------------------------------------------------------===//
10
11 // <unordered_set>
12
13 // class unordered_set
14
15 // bool empty() const noexcept;
16
17 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
18 // UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
19
20 #include <unordered_set>
21
22 #include "test_macros.h"
23
main()24 int main ()
25 {
26 std::unordered_set<int> c;
27 c.empty(); // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
28 }
29