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 // pos_type tellp();
15 
16 #include <ostream>
17 #include <cassert>
18 
19 #include "test_macros.h"
20 
21 int seekoff_called = 0;
22 
23 template <class CharT>
24 struct testbuf
25     : public std::basic_streambuf<CharT>
26 {
27     typedef std::basic_streambuf<CharT> base;
testbuftestbuf28     testbuf() {}
29 
30 protected:
31 
32     typename base::pos_type
seekofftestbuf33     seekoff(typename base::off_type off, std::ios_base::seekdir way, std::ios_base::openmode which)
34     {
35         assert(off == 0);
36         assert(way == std::ios_base::cur);
37         assert(which == std::ios_base::out);
38         ++seekoff_called;
39         return 10;
40     }
41 };
42 
main(int,char **)43 int main(int, char**)
44 {
45     {
46         std::ostream os((std::streambuf*)0);
47         assert(os.tellp() == -1);
48     }
49     {
50         testbuf<char> sb;
51         std::ostream os(&sb);
52         assert(os.tellp() == 10);
53         assert(seekoff_called == 1);
54     }
55 
56   return 0;
57 }
58