blob: 3b7417ab23e7e8873d9d784923c0ecb898cd3e70 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// XFAIL: with_system_cxx_lib=macosx10.11
// XFAIL: with_system_cxx_lib=macosx10.10
// XFAIL: with_system_cxx_lib=macosx10.9
// <istream>
// basic_istream<charT,traits>& seekg(off_type off, ios_base::seekdir dir);
#include <istream>
#include <cassert>
int seekoff_called = 0;
template <class CharT>
struct testbuf
: public std::basic_streambuf<CharT>
{
typedef std::basic_string<CharT> string_type;
typedef std::basic_streambuf<CharT> base;
private:
string_type str_;
public:
testbuf() {}
testbuf(const string_type& str)
: str_(str)
{
base::setg(const_cast<CharT*>(str_.data()),
const_cast<CharT*>(str_.data()),
const_cast<CharT*>(str_.data()) + str_.size());
}
CharT* eback() const {return base::eback();}
CharT* gptr() const {return base::gptr();}
CharT* egptr() const {return base::egptr();}
protected:
typename base::pos_type seekoff(typename base::off_type off,
std::ios_base::seekdir,
std::ios_base::openmode which)
{
assert(which == std::ios_base::in);
++seekoff_called;
return off;
}
};
int main()
{
{
testbuf<char> sb(" 123456789");
std::istream is(&sb);
is.seekg(5, std::ios_base::cur);
assert(is.good());
assert(seekoff_called == 1);
is.seekg(-1, std::ios_base::beg);
assert(is.fail());
assert(seekoff_called == 2);
}
{
testbuf<wchar_t> sb(L" 123456789");
std::wistream is(&sb);
is.seekg(5, std::ios_base::cur);
assert(is.good());
assert(seekoff_called == 3);
is.seekg(-1, std::ios_base::beg);
assert(is.fail());
assert(seekoff_called == 4);
}
{
testbuf<char> sb(" 123456789");
std::istream is(&sb);
is.setstate(std::ios_base::eofbit);
assert(is.eof());
is.seekg(5, std::ios_base::beg);
assert(is.good());
assert(!is.eof());
}
}
|
