[OkayPhysicist]

The with statement in Elixir already allows for abitrary expressions between the with and the do. I'm not sure what I'm missing here.

[mononcqc]

You're right. After all these years (and even writing a book that had Elixir snippets in it) I had never seen a single example showing it was possible and did not know it could do it.

Well there you go, I guess the pattern is equivalent but incidental.