Cost of assoc array?

[Chris via Digitalmars-d-learn]

On Wednesday, 14 May 2014 at 10:20:51 UTC, bearophile wrote:
> Chris:
>
>> Is there any huge difference as regards performance and memory 
>> footprint between the two? Or is 2. basically 1. under the 
>> hood?
>
> An associative array is a rather more complex data structure, 
> so if you don't need it, use something simpler. There is 
> difference in both the amount of memory used and performance 
> (in many cases such difference doesn't matter). In D there are 
> also differences in the way they are initialized from a null or 
> fat null.
>
> Bye,
> bearophile

Thanks. Do you mean the difference is negligible in many cases? 
I'm not sure, because changing it would be a breaking change in 
the old code, meaning I would have to change various methods.