Thorsten Ottosen wrote:
Andrei Alexandrescu skrev:
Mathias Gaunard wrote:
You would pass two adjacent ranges, like D's bringToFront (a generalization of STL's rotate, see http://www.digitalmars.com/d/2.0/phobos/std_algorithm.html) takes.
Nice idea, that could work. But how can I generate those two adjacent ranges in the first place at reasonable costs? Do ranges requires to provide a constant time "complement" primitive?
There's no such need (a range could define it though).
A design that has a bidirectional iterator walking freely up and down between two limits would be difficult to port to ranges. (If the iterator is random-access, things are trivial.) Ranges can only shrink, they never grow unless assigned from the outside. So when you move one direction it would be difficult to grow one range (shrinking the other is easy). That design would benefit from letting the iterator abstraction exposed.
Couldn't it be done with a special range that stores three iterators?
Yes, but not within the current primitive set. Sebastian's suggested interface extension should work. Andrei