2017-04-12 13:17 GMT+02:00 Guillermo Polito <guillermopolito@gmail.com>:

�� 1) each instance of A is becomed into its corresponding instance of A'
�� 2) finally we become class A into A'
�� This step will make that old instances of A now have:
�� - the old format
�� - but point to the new class A

step 1) ensures that there are no instances of class A anymore.

Check following script:

c1 := Class1 new.
c2 := Class2 new.
c1 becomeForward: c2.
Class1 allInstances "=> #()".

And full migration is executed in high priority uninterrupted process to ensure that between 1) and 2) nobody will instantiate Class1��