How do you compare NSFontSymbolicTraits and NSFontBoldTrait in Swift?

I'm trying to bitwise compare NSFontSymbolicTraits and NSFontBoldTrait in Swift.

In Objective-C it'd be done like this:

BOOL isBold = (fontDescriptorSymbolicTraits & UIFontDescriptorTraitBold);

So I'm thinking it should be this in Swift:

let isBold:Bool = font.fontDescriptor.symbolicTraits & NSFontBoldTrait

...However that results in the following error:

Cannot invoke '&' with an argument list of type '(NSFontSymbolicTraits, Int)'

Anyone know what I'm missing? Any help would be greatly appreciated.

Notes:

• I've Googled like a madman and spend hours trying to find a solution and read through the documentation for NSFontDescriptor and the other NSFont-related classes.
• I don't know Obj-C very well so I don't know if it's because the NSFont*Trait constants are implemented differently in Swift? Not even sure if that's the case.

In Swift, NSFontSymbolicTraits is a type alias for UInt32. So to check for the existence of a particular trait, you need to compare the result of your bitwise & to zero. Unfortunately, the individual constraints have been imported as type Int, so you also need to convert them to the right type:

let isBold = 0 != (font.fontDescriptor.symbolicTraits & NSFontSymbolicTraits(NSFontBoldTrait))

If you wanted to do this in iOS (instead of OS X), UIFont has a different implementation. UIFontDescriptorSymbolicTraits is a RawOptionSetType, so you compare the result of your & with nil:

let isBold = nil != (font.fontDescriptor().symbolicTraits & UIFontDescriptorSymbolicTraits.TraitBold)