Determine if Any.Type is Optional

Question

I’m trying to determine if a given type t (Any.Type) is an optional type, I’m using this test

t is Optional.Type
         


        

Answer 1

You can do something like this:

extension Mirror {
    static func isOptional(any: Any) -> Bool {
        guard let style = Mirror(reflecting: any).displayStyle,
            style == .optional else { return false }
        return true
    }
}

Usage:

XCTAssertTrue(Mirror.isOptional(any: Optional(1)))

Or if you need to cast from Any to Optional

protocol _Optional {
    var isNil: Bool { get }
}

extension Optional: _Optional {
    var isNil: Bool { return self == nil }
}

func isNil (_ input: Any) -> Bool {
    return (input as? _Optional)?.isNil ?? false
}

Usage:

isNil(nil as String?) // true
isNil("") // false