So which is it, then? Does keeping size separate "blows your CPU cache"¹ or not? You can't argue it does in one case (Rust) but not in your case…
(And note that the representation you're responding to is not really a "header", in the same sense that the trailing null is a "footer". The representation does not require the length be contiguous with the data, but that's what upthread was trying to say in the first place.)
So now you are arguing that by default your strings should come with a length? Great!
If you want that, you might as well bake that length into the string type by default (and use a specialised type, perhaps a naked raw pointer into the string) for when you don't want to pass the length.
