Swift find function which takes predicate closure

find.swift

import Foundation

func find<C : Collection>(source: C, includeElement: (C.GeneratorType.Element) -> Bool) -> C.IndexType? {

    for i in indices(source) {
        if includeElement(source[i]) {
            return i;
        }
    }

    return nil
}

// Updated for Swift 1.2

func find<C : CollectionType>(source: C, predicate: (C.Generator.Element) -> Bool) -> C.Index? {
    for i in indices(source) {
        if predicate(source[i]) {
            return i
        }
    }

    return nil
}