Swift is still very new, but all kinds of interesting libraries are being created around it. Dollar is a great example, providing useful functional programming language helpers. There are 2 parts to the library — Dollar is purely functional and Cent includes extension to built-in classes. The GitHub repository has many examples, but here's a few highlights:

The Swift equivalent for Objective C's isKindOfClass: is the is operator.

You can do:

if obj is UIView {
    //do something
} else {
    //do something else
}

If you are going to use obj, you might as well do:

if let v = obj as? UIView {
    //do something with v
} else {
    //do something else
}

You can use is and as? in the same way to test for protocols.

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