libstdc++-v3/include/experimental/iterator

   1 // <experimental/iterator> -*- C++ -*-
   2
   3 // Copyright (C) 2015-2019 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  */
  28
  29 //
  30 // N4336 Working Draft, C++ Extensions for Library Fundamentals, Version 2
  31 //
  32
  33 #ifndef _GLIBCXX_EXPERIMENTAL_ITERATOR
  34 #define _GLIBCXX_EXPERIMENTAL_ITERATOR 1
  35
  36 #pragma GCC system_header
  37
  38 #if __cplusplus >= 201402L
  39
  40 #include <iterator>
  41 #include <iosfwd>
  42 #include <experimental/type_traits>
  43
  44 namespace std _GLIBCXX_VISIBILITY(default)
  45 {
  46 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  47
  48 namespace experimental
  49 {
  50 inline namespace fundamentals_v2
  51 {
  52 #define __cpp_lib_experimental_ostream_joiner 201411
  53
  54   /// Output iterator that inserts a delimiter between elements.
  55   template<typename _DelimT, typename _CharT = char,
  56            typename _Traits = char_traits<_CharT>>
  57   class ostream_joiner
  58   {
  59   public:
  60     typedef _CharT                              char_type;
  61     typedef _Traits                             traits_type;
  62     typedef basic_ostream<_CharT, _Traits>      ostream_type;
  63     typedef output_iterator_tag                 iterator_category;
  64     typedef void                                value_type;
  65     typedef void                                difference_type;
  66     typedef void                                pointer;
  67     typedef void                                reference;
  68
  69     ostream_joiner(ostream_type& __os, const _DelimT& __delimiter)
  70     noexcept(is_nothrow_copy_constructible_v<_DelimT>)
  71     : _M_out(std::__addressof(__os)), _M_delim(__delimiter)
  72     { }
  73
  74     ostream_joiner(ostream_type& __os, _DelimT&& __delimiter)
  75     noexcept(is_nothrow_move_constructible_v<_DelimT>)
  76     : _M_out(std::__addressof(__os)), _M_delim(std::move(__delimiter))
  77     { }
  78
  79     template<typename _Tp>
  80       ostream_joiner&
  81       operator=(const _Tp& __value)
  82       {
  83         if (!_M_first)
  84           *_M_out << _M_delim;
  85         _M_first = false;
  86         *_M_out << __value;
  87         return *this;
  88       }
  89
  90     ostream_joiner& operator*() noexcept { return *this; }
  91     ostream_joiner& operator++() noexcept { return *this; }
  92     ostream_joiner& operator++(int) noexcept { return *this; }
  93
  94   private:
  95     ostream_type* _M_out;
  96     _DelimT _M_delim;
  97     bool _M_first = true;
  98   };
  99
 100   /// Object generator for ostream_joiner.
 101   template<typename _CharT, typename _Traits, typename _DelimT>
 102     inline ostream_joiner<decay_t<_DelimT>, _CharT, _Traits>
 103     make_ostream_joiner(basic_ostream<_CharT, _Traits>& __os,
 104                         _DelimT&& __delimiter)
 105     { return { __os, std::forward<_DelimT>(__delimiter) }; }
 106 } // namespace fundamentals_v2
 107 } // namespace experimental
 108
 109 _GLIBCXX_END_NAMESPACE_VERSION
 110 } // namespace std
 111
 112 #endif // __cplusplus <= 201103L
 113
 114 #endif // _GLIBCXX_EXPERIMENTAL_ITERATOR