package slicesx

/*
Last returns the last item/element in slice s.

e will be the nil/zero value of the slice element type
if the slice length is 0.
*/
func Last[S ~[]E, E any](s S) (e E) {

	var idx int = LastIndex(s)

	if idx < 0 {
		return
	}

	e = s[idx]

	return
}

/*
LastIndex returns the index of the last element in slice s.

If s is empty, idx will be -1.
If s is nil, idx will be -2.
*/
func LastIndex[S ~[]E, E any](s S) (idx int) {

	var l int = len(s)

	idx = -2
	if s != nil {
		idx++
	}
	if l == 0 {
		return
	}

	idx = l - 1

	return
}