How to generate one pointer for the parameterized class itself?

SystemVerilog
,
2

In reply to aug_com:

Unfortunately, SystemVerilog treats

a_xaction vr_cpy;

the same as

a_xaction#( /* default parameter values */ ) vr_cpy;

You need to add specific parameters.

a_xaction #(N_SZ, F_SZ) vr_cpy;

. You may want to take a look at section 8.25.1 Class resolution operator for parameterized classes in the 1800-2012 LRM for related issues.