go interface example

main.go

package main

import (
	"fmt"
)

type Movable interface {
	Translate(dx int, dy int)
}

type Position struct {
	x int
	y int
}

func (p *Position) Translate(dx int, dy int) {
	p.x += dx
	p.y += dy
}

func main() {
	var m Movable = &Position{
		x: 0,
		y: 0,
	}

	m.Translate(100, 200)

	fmt.Printf("(x, y) = (%d, %d)\n", m.(*Position).x, m.(*Position).y) // (x, y) = (100, 200)
}