             converter: MustacheBox.Converter(arrayValue: { map(GeneratorSequence(NSFastGenerator(self))) { BoxAnyObject($0) } }),
             mustacheSubscript: { (key: String) in
                 switch key {
-                case "isEmpty":
-                    return Box(self.count == 0)
                 case "count":
                     return Box(self.count)
                 case "anyObject":

                    // Support for both Objective-C and Swift arrays.
                    return Box(count)
                    
                case "isEmpty":
                    // Support for Swift arrays.
                    return Box(count == 0)
                    
                case "firstObject", "first":
                    // Support for both Objective-C and Swift arrays.
                    if count > 0 {

    
    Sets can be queried for the following key:
    
    - count: number of elements in the set
    - anyObject: any object of the set
    
    ::
    
      // Renders "3" and "0"
      template = Template(string: "{{set.count}}")!
      template.render(Box(["set": NSSet(objects: 1,2,3)]))!
