Associative array key order

[Daniel Kozak]

On Wednesday, 31 July 2013 at 14:55:55 UTC, Dicebot wrote:
> On Wednesday, 31 July 2013 at 14:43:21 UTC, Daniel Kozak wrote:
>> is there a way for AA to behave same as PHP?
>
> I doubt it. This snippet suggests that AA's in PHP are not 
> simply AA's and do additionally track insertion order (or use 
> some similar trick). Data in associative arrays is organized in 
> a way that allows fast key lookup and iterating in an original 
> order requires tracking extra state. Contrary to PHP, D does 
> care about performance so I see no way this can happen 
> automatically.

I implemented my own OrderedAA type, which is able to preserve 
insert order and is a little faster and take less memory(30%) 
then the builtin one :-).

But definitly there will be some cases where my own 
implementation doesn't beat the builtin one.