Assosiative array pop

[seany via Digitalmars-d-learn]

Given an assosiative array : int[string] k, is there a way 
(either phobos or tango) to pop the first element of this array 
and append it to another array?

I can come up with a primitive soluiton:

int[string] k;
// populate k here

int[string] j;


foreach(sttring key, int val; k)
{

j[key] = val;
break;
}

but could it be better? it is wroth noting that the keys are not 
known beforehand.