import (
	"fmt"
	"sort"
)

type Sequence []int

func (s Sequence) Len() int {
	return len(s)
}

func (s Sequence) Less(i, j int) bool {
	return s[i] < s[j]
}

func (s Sequence) Swap(i, j int) {
	s[i], s[j] = s[j], s[i]
}

func (s Sequence) Copy() Sequence {
	copy := make(Sequence, 0, len(s))
	return append(copy, s...)
}

func main() {
	s := Sequence{3, 4, 5, 1, 2, 0}
	t := s.Copy()
	fmt.Println(t)
	sort.Sort(t) // Sort becomes available for type Sequence because we
		     // implemented the required Len, Less, Swap methods.
	fmt.Println(fmt.Sprint([]int(t)))

}