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// <sstream>
10
11// template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
12// class basic_stringbuf
13
14// int_type pbackfail(int_type c = traits::eof());
15
16#include <sstream>
17#include <cassert>
18
19#include "test_macros.h"
20
21template <class CharT>
22struct testbuf
23 : public std::basic_stringbuf<CharT>
24{
25 typedef std::basic_stringbuf<CharT> base;
26 explicit testbuf(const std::basic_string<CharT>& str,
27 std::ios_base::openmode which = std::ios_base::in | std::ios_base::out)
28 : base(str, which) {}
29
30 typename base::int_type
31 pbackfail(typename base::int_type c = base::traits_type::eof())
32 {return base::pbackfail(c);}
33
34 void pbump(int n) {base::pbump(n);}
35};
36
37int main(int, char**)
38{
39 // check pbackfail
40 {
41 testbuf<char> tb("");
42 tb.pbackfail();
43 }
44 {
45 testbuf<char> sb("123", std::ios_base::in);
46 assert(sb.sgetc() == '1');
47 assert(sb.snextc() == '2');
48 assert(sb.snextc() == '3');
49 assert(sb.sgetc() == '3');
50 assert(sb.snextc() == std::char_traits<char>::eof());
51 assert(sb.pbackfail('3') == '3');
52 assert(sb.pbackfail('3') == std::char_traits<char>::eof());
53 assert(sb.pbackfail('2') == '2');
54 assert(sb.pbackfail(std::char_traits<char>::eof()) != std::char_traits<char>::eof());
55 assert(sb.pbackfail(std::char_traits<char>::eof()) == std::char_traits<char>::eof());
56 assert(sb.str() == "123");
57 }
58 {
59 testbuf<char> sb("123");
60 assert(sb.sgetc() == '1');
61 assert(sb.snextc() == '2');
62 assert(sb.snextc() == '3');
63 assert(sb.sgetc() == '3');
64 assert(sb.snextc() == std::char_traits<char>::eof());
65 assert(sb.pbackfail('3') == '3');
66 assert(sb.pbackfail('3') == '3');
67 assert(sb.pbackfail(std::char_traits<char>::eof()) != std::char_traits<char>::eof());
68 assert(sb.pbackfail(std::char_traits<char>::eof()) == std::char_traits<char>::eof());
69 assert(sb.str() == "133");
70 }
71#ifndef TEST_HAS_NO_WIDE_CHARACTERS
72 {
73 testbuf<wchar_t> sb(L"123", std::ios_base::in);
74 assert(sb.sgetc() == L'1');
75 assert(sb.snextc() == L'2');
76 assert(sb.snextc() == L'3');
77 assert(sb.sgetc() == L'3');
78 assert(sb.snextc() == std::char_traits<wchar_t>::eof());
79 assert(sb.pbackfail(L'3') == L'3');
80 assert(sb.pbackfail(L'3') == std::char_traits<wchar_t>::eof());
81 assert(sb.pbackfail(L'2') == L'2');
82 assert(sb.pbackfail(std::char_traits<wchar_t>::eof()) != std::char_traits<wchar_t>::eof());
83 assert(sb.pbackfail(std::char_traits<wchar_t>::eof()) == std::char_traits<wchar_t>::eof());
84 assert(sb.str() == L"123");
85 }
86 {
87 testbuf<wchar_t> sb(L"123");
88 assert(sb.sgetc() == L'1');
89 assert(sb.snextc() == L'2');
90 assert(sb.snextc() == L'3');
91 assert(sb.sgetc() == L'3');
92 assert(sb.snextc() == std::char_traits<wchar_t>::eof());
93 assert(sb.pbackfail(L'3') == L'3');
94 assert(sb.pbackfail(L'3') == L'3');
95 assert(sb.pbackfail(std::char_traits<wchar_t>::eof()) != std::char_traits<wchar_t>::eof());
96 assert(sb.pbackfail(std::char_traits<wchar_t>::eof()) == std::char_traits<wchar_t>::eof());
97 assert(sb.str() == L"133");
98 }
99#endif
100
101 return 0;
102}
103

source code of libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.virtuals/pbackfail.pass.cpp