I got an error when I was trying to draw gradient in Swift code:

GradientView.swift:31:40: Could not find an overload for '__conversion' that accepts the supplied arguments

Here is my code:

    let context : CGContextRef = UIGraphicsGetCurrentContext()
    let locations :CGFloat[] = [ 0.0, 0.25, 0.5, 0.75 ]
    let colors = [UIColor.redColor().CGColor,UIColor.greenColor().CGColor,UIColor.blueColor().CGColor,                         UIColor.yellowColor().CGColor]
    let colorspace : CGColorSpaceRef = CGColorSpaceCreateDeviceRGB()
    let gradient : CGGradientRef = CGGradientCreateWithColors(colorspace, colors, locations)
    //CGGradientCreateWithColors(colorspace,colors,locations)
    let startPoint : CGPoint = CGPointMake(0, 0)
    let endPoint : CGPoint = CGPointMake(500,500)
    CGContextDrawLinearGradient(context, gradient,startPoint, endPoint, 0);

The problem is the CGGradientCreateWithColors takes CFArray not a normal Swift Array. I have no idea how to convert CFArray to Array and can't find anything in Apple's document. Any idea? Thanks