package ucontainer

// Optional is an optional value.
type Optional[T any] struct {
	value T
	exists bool
}

// Value returns the value and true if the value exists. If not, it returns the
// last set value and false.
func (this *Optional[T]) Value () (T, bool) {
	return this.value, this.exists
}

// Set sets the value.
func (this *Optional[T]) Set (value T) {
	this.value = value
	this.exists = true
}

// Unset unsets the value.
func (this *Optional[T]) Unset () {
	var zero T
	this.value = zero
	this.exists = false
}

// Exists returns if the value is currently set.
func (this *Optional[T]) Exists () bool {
	return this.exists
}