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 // XFAIL: with_system_cxx_lib=macosx10.7
11 
12 // <istream>
13 
14 // basic_istream<charT,traits>& read(char_type* s, streamsize n);
15 
16 #include <istream>
17 #include <cassert>
18 
19 template <class CharT>
20 struct testbuf
21     : public std::basic_streambuf<CharT>
22 {
23     typedef std::basic_string<CharT> string_type;
24     typedef std::basic_streambuf<CharT> base;
25 private:
26     string_type str_;
27 public:
28 
29     testbuf() {}
30     testbuf(const string_type& str)
31         : str_(str)
32     {
33         base::setg(const_cast<CharT*>(str_.data()),
34                    const_cast<CharT*>(str_.data()),
35                    const_cast<CharT*>(str_.data()) + str_.size());
36     }
37 
38     CharT* eback() const {return base::eback();}
39     CharT* gptr() const {return base::gptr();}
40     CharT* egptr() const {return base::egptr();}
41 };
42 
43 int main()
44 {
45     {
46         testbuf<char> sb(" 123456789");
47         std::istream is(&sb);
48         char s[5];
49         is.read(s, 5);
50         assert(!is.eof());
51         assert(!is.fail());
52         assert(std::string(s, 5) == " 1234");
53         assert(is.gcount() == 5);
54         is.read(s, 5);
55         assert(!is.eof());
56         assert(!is.fail());
57         assert(std::string(s, 5) == "56789");
58         assert(is.gcount() == 5);
59         is.read(s, 5);
60         assert( is.eof());
61         assert( is.fail());
62         assert(is.gcount() == 0);
63     }
64     {
65         testbuf<wchar_t> sb(L" 123456789");
66         std::wistream is(&sb);
67         wchar_t s[5];
68         is.read(s, 5);
69         assert(!is.eof());
70         assert(!is.fail());
71         assert(std::wstring(s, 5) == L" 1234");
72         assert(is.gcount() == 5);
73         is.read(s, 5);
74         assert(!is.eof());
75         assert(!is.fail());
76         assert(std::wstring(s, 5) == L"56789");
77         assert(is.gcount() == 5);
78         is.read(s, 5);
79         assert( is.eof());
80         assert( is.fail());
81         assert(is.gcount() == 0);
82     }
83 }
84