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 // <streambuf>
10 
11 // template <class charT, class traits = char_traits<charT> >
12 // class basic_streambuf;
13 
14 // int_type sputbackc(char_type c);
15 
16 #include <streambuf>
17 #include <cassert>
18 
19 #include "test_macros.h"
20 
21 int pbackfail_called = 0;
22 
23 struct test
24     : public std::basic_streambuf<char>
25 {
26     typedef std::basic_streambuf<char> base;
27 
28     test() {}
29 
30     void setg(char* gbeg, char* gnext, char* gend)
31     {
32         base::setg(gbeg, gnext, gend);
33     }
34 
35 protected:
36     int_type pbackfail(int_type = traits_type::eof())
37     {
38         ++pbackfail_called;
39         return 'a';
40     }
41 };
42 
43 int main(int, char**)
44 {
45     {
46         test t;
47         assert(pbackfail_called == 0);
48         assert(t.sputbackc('A') == 'a');
49         assert(pbackfail_called == 1);
50         char in[] = "ABC";
51         t.setg(in, in+1, in+sizeof(in));
52         assert(t.sputbackc('A') == 'A');
53         assert(pbackfail_called == 1);
54         assert(t.sputbackc('A') == 'a');
55         assert(pbackfail_called == 2);
56     }
57 
58   return 0;
59 }
60