How do I define an associative array of queues?

SystemVerilog
, , ,
10

Hi All,
Here i am pushing the associative array to the associative array of queue.
But i am facing the “asssignment operator type check failed” error.

//Associative array declaration
bit [15:0] memory[int];

//Associative array of queue declaration
bit [15:0] assoc_queue[int][$];

//Here i am pushing to the value to memory
   memory[5]  = 16'h5;
   memory[22] = 16'h5;
   etc ,....

//Below i am pushing memory to assoc_queue.I want to push before i am collecting all the memory elements to assoc_queue.

assoc_queue[1].push_back(memory);

Thanks in Advance
Rajaraman