]>
Commit | Line | Data |
---|---|---|
7c673cae FG |
1 | [/ |
2 | Copyright 2010 Neil Groves | |
3 | Distributed under the Boost Software License, Version 1.0. | |
4 | (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
5 | /] | |
6 | [section:style_guide Terminology and style guidelines] | |
7 | ||
8 | The use of a consistent terminology is as important for __ranges__ and range-based algorithms as it is for iterators and iterator-based algorithms. If a conventional set of names are adopted, we can avoid misunderstandings and write generic function prototypes that are [*/self-documenting/]. | |
9 | ||
10 | Since ranges are characterized by a specific underlying iterator type, we get a type of range for each type of iterator. Hence we can speak of the following types of ranges: | |
11 | ||
12 | * [*/Value access/] category: | |
13 | * Readable Range | |
14 | * Writeable Range | |
15 | * Swappable Range | |
16 | * Lvalue Range | |
17 | * [*/Traversal/] category: | |
18 | * __single_pass_range__ | |
19 | * __forward_range__ | |
20 | * __bidirectional_range__ | |
21 | * __random_access_range__ | |
22 | ||
23 | Notice how we have used the categories from the __new_style_iterators__. | |
24 | ||
25 | Notice that an iterator (and therefore an range) has one [*/traversal/] property and one or more properties from the [*/value access/] category. So in reality we will mostly talk about mixtures such as | |
26 | ||
27 | * Random Access Readable Writeable Range | |
28 | * Forward Lvalue Range | |
29 | ||
30 | By convention, we should always specify the [*/traversal/] property first as done above. This seems reasonable since there will only be one [*/traversal/] property, but perhaps many [*/value access/] properties. | |
31 | ||
32 | It might, however, be reasonable to specify only one category if the other category does not matter. For example, the __iterator_range__ can be constructed from a Forward Range. This means that we do not care about what [*/value access/] properties the Range has. Similarly, a Readable Range will be one that has the lowest possible [*/traversal/] property (Single Pass). | |
33 | ||
34 | As another example, consider how we specify the interface of `std::sort()`. Algorithms are usually more cumbersome to specify the interface of since both [*/traversal/] and [*/value access/] properties must be exactly defined. The iterator-based version looks like this: | |
35 | ||
36 | `` | |
37 | template< class RandomAccessTraversalReadableWritableIterator > | |
38 | void sort( RandomAccessTraversalReadableWritableIterator first, | |
39 | RandomAccessTraversalReadableWritableIterator last ); | |
40 | `` | |
41 | ||
42 | For ranges the interface becomes | |
43 | ||
44 | `` | |
45 | template< class RandomAccessReadableWritableRange > | |
46 | void sort( RandomAccessReadableWritableRange& r ); | |
47 | `` | |
48 | ||
49 | [endsect] | |
50 |