ceph/src/boost/libs/regex/doc/unicode_iterators.qbk

   1 [/
   2   Copyright 2006-2007 John Maddock.
   3   Distributed under the Boost Software License, Version 1.0.
   4   (See accompanying file LICENSE_1_0.txt or copy at
   5   http://www.boost.org/LICENSE_1_0.txt).
   6 ]
   7
   8 [section:uni_iter Unicode Iterators]
   9
  10 [h4 Synopsis]
  11
  12 ``#include <boost/regex/pending/unicode_iterator.hpp>``
  13
  14    template <class BaseIterator, class U16Type = ::boost::uint16_t>
  15    class u32_to_u16_iterator;
  16
  17    template <class BaseIterator, class U32Type = ::boost::uint32_t>
  18    class u16_to_u32_iterator;
  19
  20    template <class BaseIterator, class U8Type = ::boost::uint8_t>
  21    class u32_to_u8_iterator;
  22
  23    template <class BaseIterator, class U32Type = ::boost::uint32_t>
  24    class u8_to_u32_iterator;
  25
  26    template <class BaseIterator>
  27    class utf16_output_iterator;
  28
  29    template <class BaseIterator>
  30    class utf8_output_iterator;
  31
  32
  33 [h4 Description]
  34
  35 This header contains a selection of iterator adaptors that make a sequence of characters in one
  36 encoding "look like" a read-only sequence of characters in another encoding.
  37
  38    template <class BaseIterator, class U16Type = ::boost::uint16_t>
  39    class u32_to_u16_iterator
  40    {
  41       u32_to_u16_iterator();
  42       u32_to_u16_iterator(BaseIterator start_position);
  43
  44       // Other standard BidirectionalIterator members here...
  45    };
  46
  47 A Bidirectional iterator adapter that makes an underlying sequence of UTF32 characters look like
  48 a (read-only) sequence of UTF16 characters.  The UTF16 characters are encoded in the platforms
  49 native byte order.
  50
  51    template <class BaseIterator, class U32Type = ::boost::uint32_t>
  52    class u16_to_u32_iterator
  53    {
  54       u16_to_u32_iterator();
  55       u16_to_u32_iterator(BaseIterator start_position);
  56       u16_to_u32_iterator(BaseIterator start_position, BaseIterator start_range, BaseIterator end_range);
  57
  58       // Other standard BidirectionalIterator members here...
  59    };
  60
  61 A Bidirectional iterator adapter that makes an underlying sequence of UTF16 characters
  62 (in the platforms native byte order) look like a (read-only) sequence of UTF32 characters.
  63
  64 The three-arg constructor of this class takes the start and end of the underlying sequence
  65 as well as the position to start iteration from.  This constructor validates that the
  66 underlying sequence has validly encoded endpoints: this prevents accidentally incrementing/decrementing
  67 past the end of the underlying sequence as a result of invalid UTF16 code sequences at the endpoints
  68 of the underlying range.
  69
  70    template <class BaseIterator, class U8Type = ::boost::uint8_t>
  71    class u32_to_u8_iterator
  72    {
  73       u32_to_u8_iterator();
  74       u32_to_u8_iterator(BaseIterator start_position);
  75
  76       // Other standard BidirectionalIterator members here...
  77    };
  78
  79 A Bidirectional iterator adapter that makes an underlying sequence of UTF32 characters look like
  80 a (read-only) sequence of UTF8 characters.
  81
  82    template <class BaseIterator, class U32Type = ::boost::uint32_t>
  83    class u8_to_u32_iterator
  84    {
  85       u8_to_u32_iterator();
  86       u8_to_u32_iterator(BaseIterator start_position);
  87       u8_to_u32_iterator(BaseIterator start_position, BaseIterator start_range, BaseIterator end_range);
  88
  89       // Other standard BidirectionalIterator members here...
  90    };
  91
  92 A Bidirectional iterator adapter that makes an underlying sequence of UTF8 characters
  93 look like a (read-only) sequence of UTF32 characters.
  94
  95 The three-arg constructor of this class takes the start and end of the underlying sequence
  96 as well as the position to start iteration from.  This constructor validates that the
  97 underlying sequence has validly encoded endpoints: this prevents accidentally incrementing/decrementing
  98 past the end of the underlying sequence as a result of invalid UTF8 code sequences at the endpoints
  99 of the underlying range.
 100
 101    template <class BaseIterator>
 102    class utf16_output_iterator
 103    {
 104       utf16_output_iterator(const BaseIterator& b);
 105       utf16_output_iterator(const utf16_output_iterator& that);
 106       utf16_output_iterator& operator=(const utf16_output_iterator& that);
 107
 108       // Other standard OutputIterator members here...
 109    };
 110
 111 Simple OutputIterator adapter - accepts UTF32 values as input, and forwards them to ['BaseIterator b]
 112 as UTF16.  Both UTF32 and UTF16 values are in native byte order.
 113
 114    template <class BaseIterator>
 115    class utf8_output_iterator
 116    {
 117       utf8_output_iterator(const BaseIterator& b);
 118       utf8_output_iterator(const utf8_output_iterator& that);
 119       utf8_output_iterator& operator=(const utf8_output_iterator& that);
 120
 121       // Other standard OutputIterator members here...
 122    };
 123
 124 Simple OutputIterator adapter - accepts UTF32 values as input, and forwards them to ['BaseIterator b]
 125 as UTF8.  The UTF32 input values must be in native byte order.
 126
 127 [endsect]