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 // <ostream>
10 
11 // template <class charT, class traits = char_traits<charT> >
12 //   class basic_ostream;
13 
14 // basic_ostream& flush();
15 
16 #include <ostream>
17 #include <cassert>
18 
19 #include "test_macros.h"
20 
21 int sync_called = 0;
22 
23 template <class CharT>
24 class testbuf
25     : public std::basic_streambuf<CharT>
26 {
27 public:
testbuf()28     testbuf()
29     {
30     }
31 
32 protected:
33 
34     virtual int
sync()35         sync()
36         {
37             if (sync_called++ == 1)
38                 return -1;
39             return 0;
40         }
41 };
42 
main(int,char **)43 int main(int, char**)
44 {
45     {
46         testbuf<char> sb;
47         std::ostream os(&sb);
48         os.flush();
49         assert(os.good());
50         assert(sync_called == 1);
51         os.flush();
52         assert(os.bad());
53         assert(sync_called == 2);
54     }
55 
56   return 0;
57 }
58