libcxx/include/experimental/iterator

   1 // -*- C++ -*-
   2 //===----------------------------------------------------------------------===//
   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 /*
  14 namespace 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 <__memory/addressof.h>
  56 #include <__utility/forward.h>
  57 #include <__utility/move.h>
  58 #include <experimental/__config>
  59 #include <iterator>
  60
  61 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  62 #pragma GCC system_header
  63 #endif
  64
  65 #if _LIBCPP_STD_VER > 11
  66
  67 _LIBCPP_BEGIN_NAMESPACE_LFTS
  68
  69 template <class _Delim, class _CharT = char, class _Traits = char_traits<_CharT>>
  70 class ostream_joiner {
  71 public:
  72
  73     typedef _CharT                               char_type;
  74     typedef _Traits                              traits_type;
  75     typedef basic_ostream<char_type,traits_type> ostream_type;
  76     typedef output_iterator_tag                  iterator_category;
  77     typedef void                                 value_type;
  78     typedef void                                 difference_type;
  79     typedef void                                 pointer;
  80     typedef void                                 reference;
  81
  82     ostream_joiner(ostream_type& __os, _Delim&& __d)
  83         : __output_iter(_VSTD::addressof(__os)), __delim(_VSTD::move(__d)), __first(true) {}
  84
  85     ostream_joiner(ostream_type& __os, const _Delim& __d)
  86         : __output_iter(_VSTD::addressof(__os)), __delim(__d), __first(true) {}
  87
  88
  89     template<typename _Tp>
  90     ostream_joiner& operator=(const _Tp& __v)
  91     {
  92         if (!__first)
  93             *__output_iter << __delim;
  94         __first = false;
  95         *__output_iter << __v;
  96         return *this;
  97     }
  98
  99     ostream_joiner& operator*()     _NOEXCEPT { return *this; }
 100     ostream_joiner& operator++()    _NOEXCEPT { return *this; }
 101     ostream_joiner& operator++(int) _NOEXCEPT { return *this; }
 102
 103 private:
 104     ostream_type*   __output_iter;
 105     _Delim          __delim;
 106     bool            __first;
 107 };
 108
 109
 110 template <class _CharT, class _Traits, class _Delim>
 111 ostream_joiner<typename decay<_Delim>::type, _CharT, _Traits>
 112 make_ostream_joiner(basic_ostream<_CharT, _Traits>& __os, _Delim && __d)
 113 { return ostream_joiner<typename decay<_Delim>::type, _CharT, _Traits>(__os, _VSTD::forward<_Delim>(__d)); }
 114
 115 _LIBCPP_END_NAMESPACE_LFTS
 116
 117 #endif // _LIBCPP_STD_VER > 11
 118
 119 #endif // _LIBCPP_EXPERIMENTAL_ITERATOR