Thanks for the deck! There’s one issue and one potential error I’ve had:
Issue: The cards introduce (string) format placeholders without introducing the underlying formatting. IOW, somebody who doesn’t know the latter will have no idea how and for what those placeholders are to be used.
Error: On the “How can a function be passed a reference that allows for the editing of the referenced value?” card, I don’t think “&mut david” is incorrect, syntactically and semantically. See eg. here for the four different mut combinations. Did you mean “david: &mut type”?