About ranges and iterators again: implementing next_permutation

[bearophile]

Max Klyga Wrote:

> Several weeks ago Andrei mentioned at #d irc channel that he wanted to 
> implement next_permutation STL function in Phobos.

What about instead a range, that given an array of items, yields lazily all its permutations, creating a new array each time on default, and using the same array on (compile-time) request?

Bye,
bearophile