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Cannot pass nil to two additional parameters

I am reworking an Objective-C category into a Swift extension to provide simplified methods for adding constraints. One method for even-spaced presentation has the following signature:

func addAndEquallySpaceViews(views: [UIView], leftOrTopSpace: CGFloat?, rightOrBottomSpace: CGFloat?, options: NSLayoutFormatOptions?)

I call it like this:

self.view.addAndEquallySpaceViews([view1, view2], leftOrTopSpace: nil, rightOrBottomSpace: nil, options: .AlignAllBottom)

I want to be able to pass nil in the leftOrTopSpace and rightOrBottomSpace parameters, but when I pass nil for both of them, I get a series of compile time errors. I can pass zero to either of them, but not both. Why can't I pass nil for both optional parameters?

The errors I get seem to be non-specific and not related to the relevant line,

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1 answer


These are not zero CGFloats. This is an implicit enumeration type. Here's your way:



self.view.addAndEquallySpaceViews([view1, view2], 
    leftOrTopSpace: nil, rightOrBottomSpace: nil, 
    options: NSLayoutFormatOptions.AlignAllBottom)
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