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
35This header contains a selection of iterator adaptors that make a sequence of characters in one
36encoding "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
47A Bidirectional iterator adapter that makes an underlying sequence of UTF32 characters look like
48a (read-only) sequence of UTF16 characters.  The UTF16 characters are encoded in the platforms
49native 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
61A 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
64The three-arg constructor of this class takes the start and end of the underlying sequence
65as well as the position to start iteration from.  This constructor validates that the
66underlying sequence has validly encoded endpoints: this prevents accidentally incrementing/decrementing
67past the end of the underlying sequence as a result of invalid UTF16 code sequences at the endpoints
68of 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
79A Bidirectional iterator adapter that makes an underlying sequence of UTF32 characters look like
80a (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
92A Bidirectional iterator adapter that makes an underlying sequence of UTF8 characters
93look like a (read-only) sequence of UTF32 characters.
94
95The three-arg constructor of this class takes the start and end of the underlying sequence
96as well as the position to start iteration from.  This constructor validates that the
97underlying sequence has validly encoded endpoints: this prevents accidentally incrementing/decrementing
98past the end of the underlying sequence as a result of invalid UTF8 code sequences at the endpoints
99of 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
111Simple OutputIterator adapter - accepts UTF32 values as input, and forwards them to ['BaseIterator b]
112as 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
124Simple OutputIterator adapter - accepts UTF32 values as input, and forwards them to ['BaseIterator b]
125as UTF8.  The UTF32 input values must be in native byte order.
126
127[endsect]
128