IntFormatStyle and IntegerFormatStyle: seem very similar, why are there both? And IntegerFormatStyle "is not found"

[young (rtSwift)]

IntFormatStyle and IntegerFormatStyle they seem kind of mostly the same.

But trying to use IntegerFormatStyle:

import Foundation
1234.formatted(IntegerFormatStyle.number)   // Cannot find 'IntegerFormatStyle' in scope
1234.formatted(.number)   // this works, I think it's using IntFormatStyle?

Both of these are mentioned in doc like BinaryInteger, but IntegerFormatStyle not found?

Xcode Version 13.0 beta 5 (13A5212g)

IntegerFormatStyle is tvOS 15.0+ only. Hmmm, why is tvOS is different from iOS and macOS?