Swift random(_:) function

random.swift

// Basically, a wrapper for the standard arc4random_uniform() function
// Helps to get rid of tedious integer type conversions

import UIKit // or any other framework based on Darwin, like Foundation or Darwin itself

func random <T:FixedWidthInteger> (_ upperBound: T) -> Int{
	let upperBoundAbs = abs(Int32(upperBound)) + 1 // including this one passed to the function
	let randomNumber = Int(arc4random_uniform(UInt32(upperBoundAbs)))
	return (upperBound < 0) ? -1 * randomNumber : randomNumber
}