package main

import "fmt"

var barsik Cat
var blueBird Bird

func main() {
    barsik.Fed = false
    blueBird.Hungry = true
    fmt.Println("Барсик накормлен?", barsik.Fed)
    feedAnimal(&barsik)
    fmt.Println("Барсик накормлен?", barsik.Fed)
    fmt.Println("Blue Bird голодная?", blueBird.Hungry)
    feedAnimal(&blueBird)
    fmt.Println("Blue Bird голодная?", blueBird.Hungry)
}

type Cat struct {
    Fed bool
}

type Bird struct {
    Hungry bool
}

func (c *Cat) Feed() {
    c.Fed = true
}

func (b *Bird) Feed() {
    b.Hungry = false
}

type Animal interface {
    Feed()
}

func feedAnimal(ani Animal) {
    ani.Feed()
}