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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 // operator<<(long val);
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:
testbuf()27     testbuf()
28     {
29     }
30 
str() const31     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
overflow(typename base::int_type __c=base::traits_type::eof ())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 
main()52 int main()
53 {
54     {
55         std::ostream os((std::streambuf*)0);
56         long n = 0;
57         os << n;
58         assert(os.bad());
59         assert(os.fail());
60     }
61     {
62         testbuf<char> sb;
63         std::ostream os(&sb);
64         long n = 0;
65         os << n;
66         assert(sb.str() == "0");
67     }
68     {
69         testbuf<char> sb;
70         std::ostream os(&sb);
71         long n = -10;
72         os << n;
73         assert(sb.str() == "-10");
74     }
75     {
76         testbuf<char> sb;
77         std::ostream os(&sb);
78         hex(os);
79         long n = 0xfffffff6;
80         os << n;
81         assert(sb.str() == "fffffff6");
82     }
83 }
84