Is there a way to map associative arrays

[Freddy via Digitalmars-d-learn]

On Friday, 1 August 2014 at 23:22:06 UTC, bearophile wrote:
> Freddy:
>
>> uint[uint] test;
>>
>> void main(){
>> 	test=[0:2 ,1:3 ,2:4];
>> 	writeln(test.map!(a=>a-2));
>> }
>
> If you need keys or values you have .keys .values, .byKey, 
> .byValue (the first two are eager). If you need both you are 
> out of luck, and if you want to write safe code it's better to 
> use a foreach loop. If you want to live dangerously you can use 
> a test.byKey.zip(test.byValue).
>
> Take a look in Rosettacode, there are examples for all of them.
>
> Bye,
> bearophile
Sorry, i wasn't very clear.
I wanted to know if there a way to lazily change the look up
operation
eg:
assert(test[1]==1);
assert(test[2]==2);