Duplicate a slice

One option is to allocate a new slice of the same length as original slice and use copy():

src := []int{1, 2, 3}
dst := make([]int, len(src))
copy(dst, src)

src: []int{1, 2, 3}
dst: []int{1, 2, 3}

Another option is to append() original slice to an empty slice:

src := []int{1, 2, 3}
dst := append([]int(nil), src...)

src: []int{1, 2, 3}
dst: []int{1, 2, 3}

Both versions are equally efficient.