ifchan.go

package main

import (
	"log"
	"sync"
)

type Type int

const (
	TypeAdd Type = 1
	TypeDel Type = 2
)

type CM interface {
	Channel() Type
}

type Add struct {
}

func (cm *Add) Channel() Type {
	return TypeAdd
}

var _ CM = &Add{}

type Del struct {
}

func (cm *Del) Channel() Type {
	return TypeDel
}

var _ CM = &Del{}

func work(incoming CM) {
	if add, ok := (incoming).(*Add); ok {
		log.Printf("Channel: %d\n", add.Channel())
	} else if del, ok := (incoming).(*Del); ok {
		log.Printf("Channel: %d\n", del.Channel())
	} else {
		log.Println("No known type to assert")
	}
}

func main() {
	log.Println("execute!")

	c := make(chan CM, 2)
	c <- &Del{}
	c <- &Add{}

	wg := sync.WaitGroup{}

	wg.Add(1)

	go func() {
		work(<-c)
		work(<-c)

		wg.Done()
	}()

	wg.Wait()
}