goutil/container/optional.go

package ucontainer

// Optional can either hold a value, or nothing.
type Optional[T any] struct {
	value T
	exists bool
}

// O creates a new optional with the specified value.
func O[T any] (value T) Optional[T] {
	return Optional[T] {
		value: value,
		exists: true,
	}
}

// Void returns an optional with no value.
func Void[T any] () Optional[T] {
	return Optional[T] { }
}

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

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