Associative array and ranges

[Nrgyzer]

== Auszug aus Stanislav Blinov (blinov at loniir.ru)'s Artikel
> 03.02.2011 19:34, Nrgyzer пишет:
> > == Auszug aus Steven Schveighoffer (schveiguy at yahoo.com)'s Artikel
> >> This only works if you rarely remove elements (removal in an
> >> array is an O(n) operation).
> >> -Steve
> > I already thought about using an dynamic array like T[] (which
contains all
> > elements that should be drawn) and a second like uint[hash_t]
which contains
> > the indices in the first array. But it does only shit the problem
that I can't
> > remove an index from a dynamic array.
> >
> > Thanks for your suggestions.
> >
> Why can't you?
> You can:
> 1) Get an index i from hash, do arr = arr[0..i] ~ arr[i+1..$] and
then
> reindex all arr[i..$] elements. This is costly, because, as Steven
> mentioned, such removal is O(n) plus you have to iterate all
elements
> with index >= i, and this traversal is O(n) in the worst case.
> 2) Use unstable removal. Since you store indices separately, you can
> just swap an element to be removed with last element in the array,
> shrink array using slicing (arr = arr[0..$-1]) and reindex a single
> element (the one that was previously last in the array). The
drawback is
> that this approach doesn't preserve order of elements in the array.

Ah, okay... I already tried some things with [0..i] ~ [i + 1..$] but
there was always an error and I thought, it must be done more simply.
I'm just using a simple, dynamic array and use a for-loop to remove
them. I don't need remove() often, but I thought there is any way to
do it in O(1).