TH\Maybe\Option\flatten

Converts from Option<Option<T>> to Option<T>.

Examples

$x = Option\Some("vegetables");
self::assertSame(Option\flatten(Option\some($x)), $x);
self::assertSame(Option\flatten(Option\some(Option\none())), Option\none());
self::assertSame(Option\flatten(Option\none()), Option\none());