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// <sstream>
11
12// template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
13// class basic_stringbuf
14
15// int_type pbackfail(int_type c = traits::eof());
16
17#include <sstream>
18#include <cassert>
19
20template <class CharT>
21struct testbuf
22    : public std::basic_stringbuf<CharT>
23{
24    typedef std::basic_stringbuf<CharT> base;
25    explicit testbuf(const std::basic_string<CharT>& str,
26                     std::ios_base::openmode which = std::ios_base::in | std::ios_base::out)
27        : base(str, which) {}
28
29    typename base::int_type
30        pbackfail(typename base::int_type c = base::traits_type::eof())
31        {return base::pbackfail(c);}
32
33    void pbump(int n) {base::pbump(n);}
34};
35
36int main()
37{
38    {  // sanity check
39    testbuf<char> tb("");;
40    tb.pbackfail();
41    }
42    {
43        testbuf<char> sb("123", std::ios_base::in);
44        assert(sb.sgetc() == '1');
45        assert(sb.snextc() == '2');
46        assert(sb.snextc() == '3');
47        assert(sb.sgetc() == '3');
48        assert(sb.snextc() == std::char_traits<char>::eof());
49        assert(sb.pbackfail('3') == '3');
50        assert(sb.pbackfail('3') == std::char_traits<char>::eof());
51        assert(sb.pbackfail('2') == '2');
52        assert(sb.pbackfail(std::char_traits<char>::eof()) != std::char_traits<char>::eof());
53        assert(sb.pbackfail(std::char_traits<char>::eof()) == std::char_traits<char>::eof());
54        assert(sb.str() == "123");
55    }
56    {
57        testbuf<char> sb("123");
58        assert(sb.sgetc() == '1');
59        assert(sb.snextc() == '2');
60        assert(sb.snextc() == '3');
61        assert(sb.sgetc() == '3');
62        assert(sb.snextc() == std::char_traits<char>::eof());
63        assert(sb.pbackfail('3') == '3');
64        assert(sb.pbackfail('3') == '3');
65        assert(sb.pbackfail(std::char_traits<char>::eof()) != std::char_traits<char>::eof());
66        assert(sb.pbackfail(std::char_traits<char>::eof()) == std::char_traits<char>::eof());
67        assert(sb.str() == "133");
68    }
69    {
70        testbuf<wchar_t> sb(L"123", std::ios_base::in);
71        assert(sb.sgetc() == L'1');
72        assert(sb.snextc() == L'2');
73        assert(sb.snextc() == L'3');
74        assert(sb.sgetc() == L'3');
75        assert(sb.snextc() == std::char_traits<wchar_t>::eof());
76        assert(sb.pbackfail(L'3') == L'3');
77        assert(sb.pbackfail(L'3') == std::char_traits<wchar_t>::eof());
78        assert(sb.pbackfail(L'2') == L'2');
79        assert(sb.pbackfail(std::char_traits<wchar_t>::eof()) != std::char_traits<wchar_t>::eof());
80        assert(sb.pbackfail(std::char_traits<wchar_t>::eof()) == std::char_traits<wchar_t>::eof());
81        assert(sb.str() == L"123");
82    }
83    {
84        testbuf<wchar_t> sb(L"123");
85        assert(sb.sgetc() == L'1');
86        assert(sb.snextc() == L'2');
87        assert(sb.snextc() == L'3');
88        assert(sb.sgetc() == L'3');
89        assert(sb.snextc() == std::char_traits<wchar_t>::eof());
90        assert(sb.pbackfail(L'3') == L'3');
91        assert(sb.pbackfail(L'3') == L'3');
92        assert(sb.pbackfail(std::char_traits<wchar_t>::eof()) != std::char_traits<wchar_t>::eof());
93        assert(sb.pbackfail(std::char_traits<wchar_t>::eof()) == std::char_traits<wchar_t>::eof());
94        assert(sb.str() == L"133");
95    }
96}
97