如何在Swift中打印變量的類型或類？有沒有辦法在swift中打印變量的運行時類型？例如：var now = NSDate()var soon = now.dateByAddingTimeInterval(5.0)println("\(now.dynamicType)") // Prints "(Metatype)"println("\(now.dynamicType.description()")// Prints "__NSDate" since objective-c Class objects have a "description" selectorprintln("\(soon.dynamicType.description()")// Compile-time error since ImplicitlyUnwrappedOptional<NSDate> has no "description" method在上面的例子中，我正在尋找一種方法來顯示變量“很快”是類型ImplicitlyUnwrappedOptional<NSDate>，或至少NSDate!。