Good point. I guess the reason the author finds removing from lists to be relevant is because there is no Set structure in the Go standard library. They should use a `map[t]bool`, but that is non-obvious to many programmers.
My Google search suggests that maps in Go aren’t ordered. If so this doesn’t work in place of an array.
`map[t]struct{}` saves you a few bytes per entry. Just use the `_,found := foo[key]` form of lookup
Unfortunately, map[t]bool (or map[t]struct{}) only works for special structs that happen to have equality defined for them. It's not a general purpose solution, it's just a hack.
If you ever need to delete based on value, it's a smell that a list is the wrong data structure. I'm sure there are cases in constrained environments where a linear search is heuristically okay, but generally in application development list.delete(value) is a hint that you're using the wrong data structure.