Open Radar

 
Summary:
Mistakenly passing in a function to a generic function, because you left out the parentheses after the function name can silently fail, and cause bugs.

If one has  a generic function that takes element V :

func encode<V>(element: V?, forKey key: String) {
        if let e = element {
           do something with element
        }
}

At the call site the programmer does something like this:
encoder.encode(Item.version, forKey:Item.versionKey)

Item.Version is a  function, so this was a mistake and they really meant to call the function:
encoder.encode(Item.version(), forKey:Item.versionKey)

This causes a silent failure in this case.

Notes: In this example, version should probably be a calculated property. This can probably be circumvented with conventions, and practices, however I have run in to this myself a few times, and it is kind of scary knowing this potential error can be made. I just wanted to run it by you guys to let you know.