Calculate a random delay for animation

gistfile1.swift

// Playground - noun: a place where people can play
// Running in Xcode6-Beta5

import UIKit

var delay : NSTimeInterval

// best appraoch: use arc4random_uniform (benefit you don't have to seed rand())
delay = NSTimeInterval(arc4random_uniform(900)+100) / 1000

// original calculation  
// -> 0.0
delay =  NSTimeInterval( ((Int(rand()) %  900)+100.0) / 1000.0)

// cast to Double 
// -> 0.449
delay =  NSTimeInterval( ((Double(rand()) %  900)+100.0) / 1000.0)

// just the NSTimeInterval(Double) cast 
// -> 0.573
delay =  NSTimeInterval(rand() % 900 + 100) / 1000

when i use the original code i get a error:
"could not find a overload for '/' that accepts the supplied arguments"
so i changed the Int() for a Double(), and it work magic sound now im gonna test without it

@dactrtr I'm at work now and seeing that the Int cast is returning 0.0, I think when I wrote this at home I was on an earlier release beta and now something has changed.

Using Beta-5 right now delay = NSTimeInterval(rand() % 900 + 100) / 1000 seems to be working great for me!

TBH I'm making a bunch of mistakes with casting in Swift :(