D Editions

[Gregor Mückl]

On Thursday, 30 May 2024 at 18:31:48 UTC, Atila Neves wrote:
> https://github.com/atilaneves/DIPs/blob/editions/editions.md
>
> Destroy!

How are editions going to retain compatibility across modules 
with different ABIs? I believe that combinations of inheritance 
and interface implementations may make this quite challenging.

A probably needlessly convoluted example would be this:

- a module A, edition 2024, containing a class Foo
- a module B, edition 2024+x, containing a class Bar, and
- a module C, edition 2024+y, defining an interface IFooBar and 
two classes FooBar_Foo and FooBar_Bar that derive from Foo and 
Bar respectively, but implement the IFooBar interface on top of 
them.

Any function that takes a IFooBar should be able to take both 
implementation interchangeably. But how would this work if there 
was an ABI change to the class memory layout affecting Foo and 
Bar?