libstdc++
experimental/iterator
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1// <experimental/iterator> -*- C++ -*-
2
3// Copyright (C) 2015-2021 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/** @file experimental/iterator
26 * This is a TS C++ Library header.
27 * @ingroup libfund-ts
28 */
29
30//
31// N4336 Working Draft, C++ Extensions for Library Fundamentals, Version 2
32//
33
34#ifndef _GLIBCXX_EXPERIMENTAL_ITERATOR
35#define _GLIBCXX_EXPERIMENTAL_ITERATOR 1
36
37#pragma GCC system_header
38
39#if __cplusplus >= 201402L
40
41#include <iterator>
42#include <iosfwd>
43#include <experimental/type_traits>
44
45namespace std _GLIBCXX_VISIBILITY(default)
46{
47_GLIBCXX_BEGIN_NAMESPACE_VERSION
48
49namespace experimental
50{
51inline namespace fundamentals_v2
52{
53#define __cpp_lib_experimental_ostream_joiner 201411
54
55 /// Output iterator that inserts a delimiter between elements.
56 template<typename _DelimT, typename _CharT = char,
57 typename _Traits = char_traits<_CharT>>
58 class ostream_joiner
59 {
60 public:
61 typedef _CharT char_type;
62 typedef _Traits traits_type;
63 typedef basic_ostream<_CharT, _Traits> ostream_type;
64 typedef output_iterator_tag iterator_category;
65 typedef void value_type;
66 typedef void difference_type;
67 typedef void pointer;
68 typedef void reference;
69
70 ostream_joiner(ostream_type& __os, const _DelimT& __delimiter)
71 noexcept(is_nothrow_copy_constructible_v<_DelimT>)
72 : _M_out(std::__addressof(__os)), _M_delim(__delimiter)
73 { }
74
75 ostream_joiner(ostream_type& __os, _DelimT&& __delimiter)
76 noexcept(is_nothrow_move_constructible_v<_DelimT>)
77 : _M_out(std::__addressof(__os)), _M_delim(std::move(__delimiter))
78 { }
79
80 template<typename _Tp>
81 ostream_joiner&
82 operator=(const _Tp& __value)
83 {
84 if (!_M_first)
85 *_M_out << _M_delim;
86 _M_first = false;
87 *_M_out << __value;
88 return *this;
89 }
90
91 ostream_joiner& operator*() noexcept { return *this; }
92 ostream_joiner& operator++() noexcept { return *this; }
93 ostream_joiner& operator++(int) noexcept { return *this; }
94
95 private:
96 ostream_type* _M_out;
97 _DelimT _M_delim;
98 bool _M_first = true;
99 };
100
101 /// Object generator for ostream_joiner.
102 template<typename _CharT, typename _Traits, typename _DelimT>
103 inline ostream_joiner<decay_t<_DelimT>, _CharT, _Traits>
104 make_ostream_joiner(basic_ostream<_CharT, _Traits>& __os,
105 _DelimT&& __delimiter)
106 { return { __os, std::forward<_DelimT>(__delimiter) }; }
107} // namespace fundamentals_v2
108} // namespace experimental
109
110_GLIBCXX_END_NAMESPACE_VERSION
111} // namespace std
112
113#endif // __cplusplus <= 201103L
114
115#endif // _GLIBCXX_EXPERIMENTAL_ITERATOR