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 // <ostream>
11 
12 // template <class charT, class traits = char_traits<charT> >
13 //   class basic_ostream;
14 
15 // basic_ostream& write(const char_type* s, streamsize n);
16 
17 #include <ostream>
18 #include <cassert>
19 
20 template <class CharT>
21 class testbuf
22     : public std::basic_streambuf<CharT>
23 {
24     typedef std::basic_streambuf<CharT> base;
25     std::basic_string<CharT> str_;
26 public:
27     testbuf()
28     {
29     }
30 
31     std::basic_string<CharT> str() const
32         {return std::basic_string<CharT>(base::pbase(), base::pptr());}
33 
34 protected:
35 
36     virtual typename base::int_type
37         overflow(typename base::int_type __c = base::traits_type::eof())
38         {
39             if (__c != base::traits_type::eof())
40             {
41                 int n = str_.size();
42                 str_.push_back(__c);
43                 str_.resize(str_.capacity());
44                 base::setp(const_cast<CharT*>(str_.data()),
45                            const_cast<CharT*>(str_.data() + str_.size()));
46                 base::pbump(n+1);
47             }
48             return __c;
49         }
50 };
51 
52 int main()
53 {
54     {
55         std::wostream os((std::wstreambuf*)0);
56         const wchar_t s[] = L"123456790";
57         os.write(s, sizeof(s)/sizeof(s[0])-1);
58         assert(os.bad());
59     }
60     {
61         testbuf<wchar_t> sb;
62         std::wostream os(&sb);
63         const wchar_t s[] = L"123456790";
64         os.write(s, sizeof(s)/sizeof(s[0])-1);
65         assert(os.good());
66         assert(sb.str() == s);
67     }
68     {
69         testbuf<char> sb;
70         std::ostream os(&sb);
71         const char s[] = "123456790";
72         os.write(s, sizeof(s)/sizeof(s[0])-1);
73         assert(sb.str() == s);
74         assert(os.good());
75     }
76 }
77