Re: Type t is MOD c???

[dewar@cs.nyu.edu (Robert Dewar)]

Magnus Hakansson asks:

   This probably a very simple question when you know the answer,
   but it is causing me some troubble. In "system.ads" there is a
   declaraton:

   type Address is mod Memory_Size;

   and I want to know how to assign a specific address to a pointer.
   How do I do? What is the syntax for an "address"? Is there any
   hidden packages avilable for accessing certain bytes of the memory
   of my PC, or is there any other tricks I don't know?

   Can anyone help me on this subject?

Magnus, clearly you are using Ada 95 (probably GNAT, though you did not say).
Assigning an address to a pointer can be done, but is usually not the best way
of doing things instead use:

  for x'address use expr;

where x is a variable, and expr is an address. For how to construct an
address, see the type Integer_Address and associated routines in the
package System.Storage_Elements.

If you really need to convert an address to a pointer, see package
System.Address_To_Access_Conversions.