参数化类

class stack #(type T=int);

　　local T item[];

　　task push(T a);... endtask

　　task pop(ref T a);... endtask

endclass

stack#(real) rs;

 

class D1 #(type P=real) extends stack; 　　　　// D1 includes 2 parameterized types: P, T. T is int，P is real by default.

class D1 #(type P=real) extends stack #(bit);　  // T is bit

class D1 #(type P=real) extends stack #(P);　　// T is P