ctor.pass.cpp revision 72215c2dbf0bbff4ad9f73879d346be95facdd83 
1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10// <istream>
11
12// template <class charT, class traits = char_traits<charT> >
13// class basic_istream::sentry;
14
15// explicit sentry(basic_istream<charT,traits>& is, bool noskipws = false);
16
17#include <istream>
18#include <cassert>
19
20int sync_called = 0;
21
22template <class CharT>
23struct testbuf
24    : public std::basic_streambuf<CharT>
25{
26    typedef std::basic_string<CharT> string_type;
27    typedef std::basic_streambuf<CharT> base;
28private:
29    string_type str_;
30public:
31
32    testbuf() {}
33    testbuf(const string_type& str)
34        : str_(str)
35    {
36        base::setg(const_cast<CharT*>(str_.data()),
37                   const_cast<CharT*>(str_.data()),
38                   const_cast<CharT*>(str_.data()) + str_.size());
39    }
40
41    CharT* eback() const {return base::eback();}
42    CharT* gptr() const {return base::gptr();}
43    CharT* egptr() const {return base::egptr();}
44protected:
45
46    int virtual sync()
47    {
48        ++sync_called;
49        return 1;
50    }
51};
52
53int main()
54{
55    {
56        std::istream is((testbuf<char>*)0);
57        std::istream::sentry sen(is, true);
58        assert(!(bool)sen);
59        assert(!is.good());
60        assert(is.gcount() == 0);
61        assert(sync_called == 0);
62    }
63    {
64        std::wistream is((testbuf<wchar_t>*)0);
65        std::wistream::sentry sen(is, true);
66        assert(!(bool)sen);
67        assert(!is.good());
68        assert(is.gcount() == 0);
69        assert(sync_called == 0);
70    }
71    {
72        testbuf<char> sb("   123");
73        std::istream is(&sb);
74        std::istream::sentry sen(is, true);
75        assert((bool)sen);
76        assert(is.good());
77        assert(is.gcount() == 0);
78        assert(sync_called == 0);
79        assert(sb.gptr() == sb.eback());
80    }
81    {
82        testbuf<wchar_t> sb(L"   123");
83        std::wistream is(&sb);
84        std::wistream::sentry sen(is, true);
85        assert((bool)sen);
86        assert(is.good());
87        assert(is.gcount() == 0);
88        assert(sync_called == 0);
89        assert(sb.gptr() == sb.eback());
90    }
91    {
92        testbuf<char> sb("   123");
93        std::istream is(&sb);
94        std::istream::sentry sen(is);
95        assert((bool)sen);
96        assert(is.good());
97        assert(sync_called == 0);
98        assert(sb.gptr() == sb.eback() + 3);
99    }
100    {
101        testbuf<wchar_t> sb(L"   123");
102        std::wistream is(&sb);
103        std::wistream::sentry sen(is);
104        assert((bool)sen);
105        assert(is.good());
106        assert(sync_called == 0);
107        assert(sb.gptr() == sb.eback() + 3);
108    }
109    {
110        testbuf<char> sb("      ");
111        std::istream is(&sb);
112        std::istream::sentry sen(is);
113        assert(!(bool)sen);
114        assert(is.fail());
115        assert(is.eof());
116        assert(sync_called == 0);
117        assert(sb.gptr() == sb.eback() + 6);
118    }
119    {
120        testbuf<char> sb("      ");
121        std::istream is(&sb);
122        std::istream::sentry sen(is, true);
123        assert((bool)sen);
124        assert(is.good());
125        assert(sync_called == 0);
126        assert(sb.gptr() == sb.eback());
127    }
128}
129