//enumcheck:exhaustive
type Letter byte
const (
	Alpha Letter = iota
	Beta
	Gamma
)
func Switch(x Letter) {
	switch x { // error: "missing cases Beta, Gamma and default"
	case Alpha:
		fmt.Println("alpha")
	case 4: // error: "implicit conversion of 4 to Letter"
		fmt.Println("beta")
	}
}
func Assignment() {
    var x Letter
    x = 123 // error: "implicit conversion of 123 to Letter
}

//enumcheck:exhaustive
type Expr interface{}
var _ Expr = Add{}
var _ Expr = Mul{}
type Add []Expr
type Mul []Expr
type Invalid []Expr
func Switch(x Expr) {
	switch x.(type) { // error: "missing cases Mul"
	case Add:
		fmt.Println("alpha")
	case Invalid: // error: "implicit conversion of Invalid to Expr"
		fmt.Println("beta")
	default:
		fmt.Println("unknown")
	}
}
func Assignment() {
	var x Expr
	x = 3 // error: "implicit conversion of 3 to Expr
	_ = x
}

//enumcheck:exhaustive
type Option struct{ value string }
var (
	True  = Option{"carview.php?tsp=true"}
	False = Option{"false"}
	Maybe = Option{"maybe"}
)
func DayNonExhaustive() {
	var day Option
	switch day { // want "missing cases False, Maybe and default"
	case Option{"invalid"}: // want "invalid enum for enumstruct.Option"
		fmt.Println("beta")
	case True:
		fmt.Println("beta")
	}
}

//enumcheck:relaxed
type Option string
var (
	Alpha = Option("alpha")
	Beta  = Option("beta")
)
func Relaxed() {
	var day Option
	switch day {
	case Alpha:
		fmt.Println("alpha")
	case Beta:
		fmt.Println("beta")
	}
}

//enumcheck:silent
type Option string
var (
	Alpha = Option("alpha")
	Beta  = Option("beta")
)
func NoErrorHere() {
	var day Option
	switch day {
	case Beta:
		fmt.Println("beta")
	}
}
func EnablePerSwitch() {
	var day Option
	switch day { //enumcheck:exhaustive
	case Beta:
		fmt.Println("beta")
	}
}