1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // <ostream>
11 
12 // template <class charT, class traits = char_traits<charT> >
13 // class basic_ostream::sentry;
14 
15 // ~sentry();
16 
17 #include <ostream>
18 #include <cassert>
19 
20 int sync_called = 0;
21 
22 template <class CharT>
23 struct testbuf1
24     : public std::basic_streambuf<CharT>
25 {
testbuf1testbuf126     testbuf1() {}
27 
28 protected:
29 
synctestbuf130     int virtual sync()
31     {
32         ++sync_called;
33         return 1;
34     }
35 };
36 
main()37 int main()
38 {
39     {
40         std::ostream os((std::streambuf*)0);
41         std::ostream::sentry s(os);
42         assert(!bool(s));
43     }
44     assert(sync_called == 0);
45     {
46         testbuf1<char> sb;
47         std::ostream os(&sb);
48         std::ostream::sentry s(os);
49         assert(bool(s));
50     }
51     assert(sync_called == 0);
52     {
53         testbuf1<char> sb;
54         std::ostream os(&sb);
55         std::ostream::sentry s(os);
56         assert(bool(s));
57         unitbuf(os);
58     }
59     assert(sync_called == 1);
60     {
61         testbuf1<char> sb;
62         std::ostream os(&sb);
63         try
64         {
65             std::ostream::sentry s(os);
66             assert(bool(s));
67             unitbuf(os);
68             throw 1;
69         }
70         catch (...)
71         {
72         }
73         assert(sync_called == 1);
74     }
75 }
76