Bitmask using iota in go. Playground link: https://play.golang.org/p/jKuDcNVt-iK

bitmask.go

package main

import "fmt"

const (
	A int8 = 1 << iota
	B
	C
)

func main() {
	on := A | C
	if A&on > 0 {
		fmt.Println("A is on")
	}
	if B&on > 0 {
		fmt.Println("B is on")
	}
	if C&on > 0 {
		fmt.Println("C is on")
	}
}