GLOBALANYPTR Variables

The pointer type globalanyptr is assignment compatible with every pointer type and the value nil. Anyptr is another name for the same type, provided for compatibility with older Pascals. This manual uses the term globalanyptr exclusively, but anyptr can be substituted wherever it appears.

A variable of type globalanyptr is not bound to a specific pointer type. You can assign it any pointer-type value, or compare it to any pointer-type value with the operator = or >, but you cannot dereference it.

Because a globalanyptr variable can be assigned any pointer-type value, the compiler allocates it 64 bits. If your program does not use extended address pointers, you can save space by substituting localanyptr for globalanyptr.

Your program uses extended address pointers if it declares a type or variable with the EXTNADDR compiler option. Refer to the HP Pascal/iX Reference Manual or the HP Pascal/HP-UX Reference Manual, depending on your implementation, for detailed information on compiler options.

Example

This program works the same way and takes the same amount of space if you substitute anyptr for any or every occurrence of globalanyptr. This would be true even if the program had extended address pointers.

Since the program does not have extended address pointers, it works the same way if you substitute localanyptr for any or every occurrence of globalanyptr — but it takes less space. (Compare this program with the one in the section “LOCALANYPTR Variables ”.)

PROGRAM prog (input);
TYPE
   iptr = ^integer;
   rec  = RECORD
            f1, f2 : real;
          END;
   rptr = ^rec;
VAR
      v1, d1 : iptr;
      v2, d2 : rptr;
    anyv : globalanyptr;
       b : Boolean;
BEGIN
   {Initialize v1 and v2}
   new(v1);
   new(v2);
   v1^ := 0;
   WITH v2^ DO BEGIN
      f1 := 0;
      f2 := 0;
   END;
 
   {Set anyv to v1 or v2, depending on b}
   read(b);
   IF b THEN anyv := v1 ELSE anyv := v2;
 
   {You cannot dereference anyv, because it is a globalanyptr.
    This is how you can access its data:}
   IF anyv = v1 THEN BEGIN
      d1 := anyv;
      d1^ := d1^ + 1;
   END
   ELSE BEGIN
      d2 := anyv;
      WITH d2^ DO BEGIN
         f1 := 34.6;
         f2 := 91.2;
      END;
   END;
END.