package main

import (
	"fmt"
	"sync"
	"time"
)

func printChannel(ci <-chan int, done chan<- bool) {
	defer func() { done <- true }()
	for i := range ci {
		time.Sleep(100 * time.Millisecond)
		fmt.Println(i)
	}
}

func printWaitgroup(ci <-chan int, wg *sync.WaitGroup) {
	defer func() { wg.Done() }()
	for i := range ci {
		time.Sleep(100 * time.Millisecond)
		fmt.Println(i)
	}
}

func main() {

	c := make(chan int)

	//done := make(chan bool)
	//go printChannel(c, done)

	wg := sync.WaitGroup{}
	wg.Add(1)
	go printWaitgroup(c, &wg)

	c <- 1
	c <- 2
	c <- 3
	close(c)

	//<-done
	wg.Wait()
}