On 04/03/2022 21.01, Uecker, Martin wrote:
> Am Freitag, den 04.03.2022, 20:48 +0100 schrieb Jens Maurer:

> Wasn't there also something specifically about
> the possible effects on previous observable
> behavior or do I misremember this?

Yes, there's more in the abstract machine description:

Certain other operations are described in this document as undefined (for example, the effect of attempting
to modify a const object).
[Note 1 : This document imposes no requirements on the behavior of programs that contain undefined behavior.
— end note]

A conforming implementation executing a well-formed program shall produce the same observable behavior as
one of the possible executions of the corresponding instance of the abstract machine with the same program
and the same input. However, if any such execution contains an undefined operation, this document places
no requirement on the implementation executing that program with that input (not even with regard to
operations preceding the first undefined operation).


Jens