1// -*- C++ -*-
2//===----------------------------- iterator -------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_EXPERIMENTAL_ITERATOR
11#define _LIBCPP_EXPERIMENTAL_ITERATOR
12
13/*
14namespace std {
15  namespace experimental {
16    inline namespace fundamentals_v2 {
17
18    template <class DelimT, class charT = char, class traits = char_traits<charT>>
19        class ostream_joiner {
20        public:
21         typedef charT                        char_type;
22         typedef traits                       traits_type;
23         typedef basic_ostream<charT, traits> ostream_type;
24         typedef output_iterator_tag          iterator_category;
25         typedef void                         value_type;
26         typedef void                         difference_type;
27         typedef void                         pointer;
28         typedef void                         reference;
29
30         ostream_joiner(ostream_type& s, const DelimT& delimiter);
31         ostream_joiner(ostream_type& s, DelimT&& delimiter);
32
33         template<typename T>
34         ostream_joiner& operator=(const T& value);
35
36         ostream_joiner& operator*() noexcept;
37         ostream_joiner& operator++() noexcept;
38         ostream_joiner& operator++(int) noexcept;
39   private:
40      ostream_type* out_stream;   // exposition only
41      DelimT delim;               // exposition only
42      bool first_element;         // exposition only
43   };
44
45  template <class charT, class traits, class DelimT>
46    ostream_joiner<decay_t<DelimT>, charT, traits>
47    make_ostream_joiner(basic_ostream<charT, traits>& os, DelimT&& delimiter);
48
49    } // inline namespace fundamentals_v2
50  } // namespace experimental
51} // namespace std
52
53*/
54
55#include <experimental/__config>
56
57#if _LIBCPP_STD_VER > 11
58
59#include <iterator>
60
61_LIBCPP_BEGIN_NAMESPACE_LFTS
62
63template <class _Delim, class _CharT = char, class _Traits = char_traits<_CharT>>
64class ostream_joiner {
65public:
66
67    typedef _CharT                               char_type;
68    typedef _Traits                              traits_type;
69    typedef basic_ostream<char_type,traits_type> ostream_type;
70    typedef output_iterator_tag                  iterator_category;
71    typedef void                                 value_type;
72    typedef void                                 difference_type;
73    typedef void                                 pointer;
74    typedef void                                 reference;
75
76    ostream_joiner(ostream_type& __os, _Delim&& __d)
77        : __output_iter(_VSTD::addressof(__os)), __delim(_VSTD::move(__d)), __first(true) {}
78
79    ostream_joiner(ostream_type& __os, const _Delim& __d)
80        : __output_iter(_VSTD::addressof(__os)), __delim(__d), __first(true) {}
81
82
83    template<typename _Tp>
84    ostream_joiner& operator=(const _Tp& __v)
85    {
86        if (!__first)
87            *__output_iter << __delim;
88        __first = false;
89        *__output_iter << __v;
90        return *this;
91    }
92
93    ostream_joiner& operator*()     _NOEXCEPT { return *this; }
94    ostream_joiner& operator++()    _NOEXCEPT { return *this; }
95    ostream_joiner& operator++(int) _NOEXCEPT { return *this; }
96
97private:
98    ostream_type*   __output_iter;
99    _Delim          __delim;
100    bool            __first;
101};
102
103
104template <class _CharT, class _Traits, class _Delim>
105ostream_joiner<typename decay<_Delim>::type, _CharT, _Traits>
106make_ostream_joiner(basic_ostream<_CharT, _Traits>& __os, _Delim && __d)
107{ return ostream_joiner<typename decay<_Delim>::type, _CharT, _Traits>(__os, _VSTD::forward<_Delim>(__d)); }
108
109_LIBCPP_END_NAMESPACE_LFTS
110
111#endif /* _LIBCPP_STD_VER > 11 */
112
113#endif // _LIBCPP_EXPERIMENTAL_ITERATOR
114