The Art of Assembly Language, 2nd Edition

5.20 Untyped Reference Parameters

Sometimes you will want to write a procedure to which you pass a generic memory object by reference without regard to the type of that memory object. A classic example is a procedure that zeros out some data structure. Such a procedure might have the following prototype:

procedure ZeroMem( var mem:byte; count:uns32 );

This procedure would zero out count bytes starting at the address the first parameter specifies. The problem with this procedure prototype is that HLA will complain if you attempt to pass anything other than a byte object as the first parameter. Of course, you can overcome this problem using type coercion like the following, but if you call this procedure several times with a lot of different data ...