libstdc++-v3/include/experimental/iterator

   1 // <experimental/iterator> -*- C++ -*-
   2
   3 // Copyright (C) 2015-2022 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
  45 namespace std _GLIBCXX_VISIBILITY(default)
  46 {
  47 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  48
  49 namespace experimental
  50 {
  51 inline 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