UIView's alpha property's comparison error

Question

Here is my problem:

let view = UIView()

var alpha: CGFloat = 0.2
view.alpha = alpha
if view.alpha == alpha {
    print("true: \(view.alpha)")
} else {
    print("false: \(view.alpha)") // false: 0.200000002980232
}

alpha = 0.5
view.alpha = alpha
if view.alpha == alpha {
    print("true: \(view.alpha)") // true: 0.5
} else {
    print("false: \(view.alpha)")
}

alpha = 0.9
view.alpha = alpha
if view.alpha == alpha {
    print("true: \(view.alpha)")
} else {
    print("false: \(view.alpha)")  // false: 0.899999976158142
}

var factor:CGFloat = 0.2
view.contentScaleFactor = factor
if view.contentScaleFactor == factor {
    print("true: \(view.contentScaleFactor)") // true: 0.2
} else {
    print("false: \(view.contentScaleFactor)")
}

Code above tested with Xcode 7.3 & Swift 2.2

I'm not sure if there is already a rdar address this problem or not.

Any idea why ? Or since when ?