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 // <stack>
10 
11 // const_reference top() const;
12 
13 #include <stack>
14 #include <cassert>
15 
16 int main(int, char**)
17 {
18     std::stack<int> q;
19     assert(q.size() == 0);
20     q.push(1);
21     q.push(2);
22     q.push(3);
23     const std::stack<int>& cqr = q;
24     const int& cir = cqr.top();
25     assert(cir == 3);
26 
27   return 0;
28 }
29