How to efficiently delete contiguous elements of a slice while keeping the element order?

1. the involved slice is s and its type is []E, where E is the slice element type.
2. we want to delete the elements in the subslice s[from:to] and from <= to.

Way 1: use the build-in copy function

	s = s[:from + copy(s[from:], s[to:])]

Way 2: use the build-in append function

	s = append(s[from:], s[to:]...)

Way 3: use the slices.Delete function (Since Go 1.21)

import "slices"

	s = slices.Delete(s, from, to)

Some notes

Note 1

• when from < to, the former two ways are as performant as each other.
• when from == to, the first way is almost a no-op, but the second way is not.

Note 2

	// The "clear" built-in function was introduced in Go 1.21.
	clear(s[len(s):len(s)+to-from])

	{
		temp := s[len(s):len(s)+to-from]
		for i := range temp {
			temp[i] = zeroE
		}
	}