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 // <strstream>
11 
12 // class strstreambuf
13 
14 // int_type pbackfail(int_type c = EOF);
15 
16 #include <strstream>
17 #include <cassert>
18 
19 struct test
20     : public std::strstreambuf
21 {
22     typedef std::strstreambuf base;
23     test(char* gnext_arg, std::streamsize n, char* pbeg_arg = 0)
24         : base(gnext_arg, n, pbeg_arg) {}
25     test(const char* gnext_arg, std::streamsize n)
26         : base(gnext_arg, n) {}
27 
28     virtual int_type pbackfail(int_type c = EOF) {return base::pbackfail(c);}
29 };
30 
31 int main()
32 {
33     {
34         const char buf[] = "123";
35         test sb(buf, 0);
36         assert(sb.sgetc() == '1');
37         assert(sb.snextc() == '2');
38         assert(sb.snextc() == '3');
39         assert(sb.sgetc() == '3');
40         assert(sb.snextc() == EOF);
41         assert(sb.pbackfail('3') == '3');
42         assert(sb.pbackfail('3') == EOF);
43         assert(sb.pbackfail('2') == '2');
44         assert(sb.pbackfail(EOF) != EOF);
45         assert(sb.pbackfail(EOF) == EOF);
46         assert(sb.str() == std::string("123"));
47     }
48     {
49         char buf[] = "123";
50         test sb(buf, 0);
51         assert(sb.sgetc() == '1');
52         assert(sb.snextc() == '2');
53         assert(sb.snextc() == '3');
54         assert(sb.sgetc() == '3');
55         assert(sb.snextc() == EOF);
56         assert(sb.pbackfail('3') == '3');
57         assert(sb.pbackfail('3') == '3');
58         assert(sb.pbackfail(EOF) != EOF);
59         assert(sb.pbackfail(EOF) == EOF);
60         assert(sb.str() == std::string("133"));
61     }
62 }
63