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- [/
- Copyright 2010 Neil Groves
- Distributed under the Boost Software License, Version 1.0.
- (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
- /]
- [section:style_guide Terminology and style guidelines]
- 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/].
- 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:
- * [*/Value access/] category:
- * Readable Range
- * Writeable Range
- * Swappable Range
- * Lvalue Range
- * [*/Traversal/] category:
- * __single_pass_range__
- * __forward_range__
- * __bidirectional_range__
- * __random_access_range__
- Notice how we have used the categories from the __new_style_iterators__.
- 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
- * Random Access Readable Writeable Range
- * Forward Lvalue Range
- 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.
- 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).
- 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:
- ``
- template< class RandomAccessTraversalReadableWritableIterator >
- void sort( RandomAccessTraversalReadableWritableIterator first,
- RandomAccessTraversalReadableWritableIterator last );
- ``
- For ranges the interface becomes
- ``
- template< class RandomAccessReadableWritableRange >
- void sort( RandomAccessReadableWritableRange& r );
- ``
- [endsect]
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