[jtrueb]

I agree this is useful. I also think it isn’t the end of the world to support some semblance of OOP in Rust.

If it helps you ship the business logic, sometimes it’s okay to concede some performance or other cost.

[BrainInAJar]

"sometimes" is doing a lot of work there.

Sometimes it is, but also sometimes it isn't, and Rust at least gives you a choice (you can use Arc all over the place, or if performance is critical you can be more careful about specifying lifetimes)

[jtrueb]

Arc doesn’t give you the choice until this upcasting feature lands in stable.