I may have misunderstood "you can't just concatenate different slices (e.g. to remove one item from the middle" but does [0] not do what you're talking about?

I may have misunderstood "you can't just concatenate different slices (e.g. to remove one item from the middle" but does [0] not do what you're talking about? (with the caveat that anything else sharing `a` will be mangled, obvs.) [0] https://go.dev/play/p/uQdoa3mUF00 https://go.dev/play/p/uQdoa3mUF00