We are trying to compile ovm on the vcs and and I came across some code which was giving issue with VCS but it works in modelsim. So here is what the code looks like :
typedef int pint;
typedef pint pnewint[string];
module test;
pnewint aa [string];
initial begin
aa["ss"]["ss"] = 1;
$display (”I am here in test %d \n”, aa["ss"]["ss"]);
end
endmodule
Output :
=====
VSIM 1> run
run
# I am here in test 1
#
After that I tried a direct deceleration test like :
module test;
int aa [string] [string];
initial begin
aa["ss"]["ss"] = 1;
$display (”I am here in test %d \n”, aa["ss"]["ss"]);
end
endmodule
Output :
=====
VSIM 1> run
run
# I am here in test 1
#
So basically the above statements mean that modelsim allow multi dimentional associative array creation. Now the question is does LRM allows it. I guess it does not 
.