1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // <ostream>
10 
11 // template <class charT, class traits = char_traits<charT> >
12 //   class basic_ostream;
13 
14 // basic_ostream<charT,traits>& operator<<(basic_streambuf<charT,traits>* sb);
15 
16 #include <ostream>
17 #include <cassert>
18 
19 #include "test_macros.h"
20 
21 template <class CharT>
22 class testbuf
23     : public std::basic_streambuf<CharT>
24 {
25     typedef std::basic_streambuf<CharT> base;
26     std::basic_string<CharT> str_;
27 public:
testbuf()28     testbuf()
29     {
30     }
testbuf(const std::basic_string<CharT> & str)31     testbuf(const std::basic_string<CharT>& str)
32         : str_(str)
33     {
34         base::setg(const_cast<CharT*>(str_.data()),
35                    const_cast<CharT*>(str_.data()),
36                    const_cast<CharT*>(str_.data() + str_.size()));
37     }
38 
str() const39     std::basic_string<CharT> str() const
40         {return std::basic_string<CharT>(base::pbase(), base::pptr());}
41 
42 protected:
43 
44     virtual typename base::int_type
overflow(typename base::int_type ch=base::traits_type::eof ())45         overflow(typename base::int_type ch = base::traits_type::eof())
46         {
47             if (ch != base::traits_type::eof())
48             {
49                 int n = static_cast<int>(str_.size());
50                 str_.push_back(static_cast<CharT>(ch));
51                 str_.resize(str_.capacity());
52                 base::setp(const_cast<CharT*>(str_.data()),
53                            const_cast<CharT*>(str_.data() + str_.size()));
54                 base::pbump(n+1);
55             }
56             return ch;
57         }
58 };
59 
main(int,char **)60 int main(int, char**)
61 {
62     {
63         testbuf<char> sb;
64         std::ostream os(&sb);
65         testbuf<char> sb2("testing...");
66         assert(sb.str() == "");
67         os << &sb2;
68         assert(sb.str() == "testing...");
69     }
70 #if TEST_STD_VER > 14
71 // LWG 2221 - nullptr. This is not backported to older standards modes.
72 // See https://reviews.llvm.org/D127033 for more info on the rationale.
73     {
74         testbuf<char> sb;
75         std::ostream os(&sb);
76         os << nullptr;
77         assert(sb.str().size() != 0);
78         LIBCPP_ASSERT(sb.str() == "nullptr");
79     }
80 #endif
81 
82   return 0;
83 }
84