Feature request for "friendship" of pointers in "C"

[Holger Lamm]

Am 17.03.20 um 22:41 schrieb Andreas Schwab:
> On Mär 17 2020, Holger Lamm wrote:
>
>> No. The order of elements of structures in memory is implementation
>> defined and not guaranteed to be the order of enumeration in the
>> definition.
>
> That is not true.  The first member is guaranteed to have the same
> address as the whole structure, and subsequent members have increasing
> addresses, in declaration order.

Sorry, I must confess.
ANSI C 6.5.8 (5) confirms that "... pointers  to  structure  members 
declared  later  compare  greater  than  pointers  to  members
declared  earlier  in  the  structure"; I found no definition of address 
to structure vs. address of structure member but there would be no 
reason to have padding *before* the first element.

However, I see no reason for the original request to treat both pointers 
as compatible. (I guess the request goes into the direction of not 
issuing a type warning).
Pointer address might be the same, and the resulting code be working. 
But the referenced objects are of different type, size and not compatible.

Regards,
Holger