Reading about D: few questions

[Mr. Anonymous]

On 24.12.2011 19:01, Denis Shelomovskij wrote:
> 23.12.2011 22:51, bearophile пишет:
>>> ++a[] works, but a[]++ doesn't.
>> Already known compiler bug.
>
> Is it a joke? Array expression in D are for performance reasons to
> generate x2-x100 faster code without any compiler optimisations. Link to
> one of these epic comments (even x100 more epic because of '%' use
> instead of 'x###'):
> https://github.com/D-Programming-Language/druntime/blob/master/src/rt/arraybyte.d#L1127
>
>
> But `a[]++` should store a copy of `a`, increment elements and return
> stored copy. It is hidden GC allocation. We already have a silent
> allocation in closures, but here a _really large_ peace of data can be
> allocated. Yes, this allocation sometimes can be optimized out but not
> always.
>
> IMHO, D should not have `a[]++` operator.

Why should it store a copy? o_O
I also don't see any allocations in the code on the URL above.