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:
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
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
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 );
(C) Copyright Thorsten Ottosen 2003-2004