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 Stream, class T>
12 // Stream&& operator<<(Stream&& os, const T& x);
13 
14 #include <ostream>
15 #include <cassert>
16 
17 #include "test_macros.h"
18 
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 ch=base::traits_type::eof ())37         overflow(typename base::int_type ch = base::traits_type::eof())
38         {
39             if (ch != base::traits_type::eof())
40             {
41                 int n = static_cast<int>(str_.size());
42                 str_.push_back(static_cast<CharT>(ch));
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 ch;
49         }
50 };
51 
52 struct Int {
53     int value;
54     template <class CharT>
operator <<(std::basic_ostream<CharT> & os,Int const & self)55     friend void operator<<(std::basic_ostream<CharT>& os, Int const& self) {
56         os << self.value;
57     }
58 };
59 
main(int,char **)60 int main(int, char**)
61 {
62     {
63         testbuf<char> sb;
64         std::ostream os(&sb);
65         Int const i = {123};
66         std::ostream&& result = (std::move(os) << i);
67         assert(&result == &os);
68         assert(sb.str() == "123");
69     }
70 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
71     {
72         testbuf<wchar_t> sb;
73         std::wostream os(&sb);
74         Int const i = {123};
75         std::wostream&& result = (std::move(os) << i);
76         assert(&result == &os);
77         assert(sb.str() == L"123");
78     }
79 #endif
80 
81     return 0;
82 }
83