extension Collection {
    /// Splits into two arrays, first containing elements which matching the predicate
    /// and other containting elements not matching the predicate.
    ///
    /// - Parameter isMatching: The predicate to apply.
    /// - Returns: Tuple of split arrays.
    public func split(_ isMatching: (Iterator.Element) -> Bool) -> ([Iterator.Element], [Iterator.Element]) {
        var matchingElements: [Iterator.Element] = []
        var nonMatchingElements: [Iterator.Element] = []
        for element in self {
            if isMatching(element) {
                matchingElements.append(element)
            } else {
                nonMatchingElements.append(element)
            }
        }
        return (matchingElements, nonMatchingElements)
    }
}