typecasttweet.swift

// only class types:

func myCast<MyClass: AnyObject>(value: AnyObject, type: MyClass.Type) -> MyClass? {
    return value as? MyClass
}

// any type (class, struct, etc):

func myCast1<MyClass: Any>(value: Any, type: MyClass.Type) -> MyClass? {
    return value as? MyClass
}

You don't even need the type: parameter if you're fine with relying on return-type type inference e.g. this would work if you defined the same function but without the type: parameter:

let val: Any = 5
let castVal: Int? = myCast1(value: val)

This is brilliant, thank you!

Also: http://blog.segiddins.me/2015/01/25/dynamic-casting-in-swift/

Non-optional version may be useful if you're brave / sure:

func infer<T: Any>(value: Any) -> T {
    return value as! T
}