Initialize multi dimensional associative dynamic array

[bearophile]

js.mdnq:

> myval1 = arr["Group1"][3243];  // has O(1) lookup
> myval2 = arr["Group2"][3243];  // has O(1) lookup

Another option is to use an associative array where the keys are 
Tuple!(string, int):

alias Tuple!(string, int) Tkey;
int[Tkey] arr;
myval1 = arr[Tkey("Group1", 3243)];
myval2 = arr[Tkey("Group2", 3243)];

But also take this in account:
http://d.puremagic.com/issues/show_bug.cgi?id=3789


> But when I try to access the value of the value I get an 
> exception, I believe, because I haven't initialized the value. 
> (because if I do a simple assign to the value it then works, 
> but I'm trying to check if the value exists in the first place)

Why don't you show what you are trying to do with a little 
program, plus the errors you get?

Bye,
bearophile