Problem with associative arrays

[Piotr Szturmaj]

Shouldn't dynamic array be reference type?

uint[][uint] aa;
uint[] temp;
        
aa[5] = new uint[0];
temp = aa[5]; // copy uint[] reference
temp ~= 1;
        
assert(temp.length == 1 && temp[0] == 1); // pass
assert(aa[5].length == 1 && aa[5][0] == 1); // fail

Is this a bug?