The Max_Size_In_Storage_Elements attribute is useful
in writing user-defined pool types.
Denotes the maximum value for
Size_In_Storage_Elements that could be requested by the implementation
via Allocate for an access type whose designated subtype is S. For a
type with access discriminants, if the implementation allocates space
for a coextension in the same pool as that of the object having the access
discriminant, then this accounts for any calls on Allocate that could
be performed to provide space for such coextensions. The value of this
attribute is of type
universal_integer.