kCFNumberInt64Type

kCFNumberInt64Type is a constant defined in the Core Foundation framework of Apple's operating systems. It represents a 64-bit signed integer data type. When working with Core Foundation objects, particularly CFNumber, this constant is used to specify that the underlying value being stored or retrieved is an Int64.

CFNumber is a toll-free bridged type in Objective-C, meaning it can be used interchangeably with the `NSNumber` class in Cocoa. When you create an `NSNumber` object to hold a 64-bit integer value, or when you retrieve such a value from an `NSNumber`, the underlying representation often uses the concept corresponding to kCFNumberInt64Type.

This type is crucial for handling large integer values that exceed the capacity of a standard 32-bit integer. For example, when dealing with data structures or algorithms that require precise handling of large numerical quantities, using a 64-bit integer type is often necessary. kCFNumberInt64Type ensures that Core Foundation can correctly interpret and manage these values.

In practice, developers might encounter kCFNumberInt64Type when serializing or deserializing data, interacting with lower-level C APIs, or when working with frameworks that expose Core Foundation types. Understanding this constant helps in correctly managing numerical data, especially in scenarios involving cross-platform compatibility or when interacting with systems that have specific integer size requirements.