Get properties from a swift object -- NSObject extension

IntrospectionExtensions.swift

extension NSObject {
    class var propertyNames: [String] {
        get {
            var count: UInt32 = 0
            let properties: UnsafeMutablePointer<objc_property_t> = class_copyPropertyList(self.classForCoder(), &count)
            var propertyNames: [String] = []
            for i in 0..<count {
                let property: objc_property_t = properties[Int(i)]
                if let name = String(UTF8String: property_getName(property)) {
                    propertyNames += [name]
                }
            }
            return propertyNames
        }
    }
}