5 Sep
2018
5 Sep
'18
8:45 a.m.
On 2018-09-05 15:19, Hugh Fisher wrote:
And this happens to be exactly what Apple did when they added tagged pointers to Objective-C. They told programmers not to access objectptr->isa directly, instead to use OBJECT_GETCLASS(objectptr). Then later they started implementing some objects as tagged pointers, and only code that hadn't been updated broke. OBJECT_GETCLASS was the "stable ABI"
This is a stable API, but I would guess not a stable ABI. Victor Stinner wants a stable ABI.