Word around for XCode 8.1 bug
Word around for XCode 8.1 bug

Intentionally forced unwrapped.
Workaround the error by explicitly unwrapping u:

func compare<T: Comparable>(v: T, u: T!) -> Bool {
       return v < u!
}

https://developer.apple.com/library/content/releasenotes/DeveloperTools/RN-Xcode/Introduction.html

patchthecode/JTAppleCalendar,patchthecode/JTAppleCalendar