Protocol type constraints for generics in Apple Swift

comparableGenerics.swift

/* 
 * Here the Comparable protocol is used as the type constraint
 * For equality testing the Equitable protocol would be needed
 * To print a variable it must conform to the Printable protocol
 *
 * see also:
 * https://developer.apple.com/library/prerelease/ios/documentation/General/Reference/SwiftStandardLibraryReference/Equatable.html#//apple_ref/doc/uid/TP40014608-CH17-SW1
 */
func min3a_generics<T: Comparable>(a: T, b: T, c: T) -> T {
    if a < b {
        if a < c {
            return a
        } else {
            return c
        }
    } else {
        if b < c {
            return b
        } else {
            return c
        }
    }
}