Implicitly Unwrapped Optional Types - Possible Typo?

Question

From the Swift Programming Language documentation:

Implicitly Unwrapped Optional Type

The Swift language defines the postfix ! as syntactic sugar for the named type ImplicitlyUnwrappedOptional, which is defined in the Swift standard library. In other words, the following two declarations are equivalent:

 var implicitlyUnwrappedString: String! var implicitlyUnwrappedString: String! 

In both cases, the variable implicitlyUnwrappedString is declared to have the type of an implicitly unwrapped optional string. Note that no whitespace may appear between the type and the !.

Am I missing something? Both lines look exactly the same to me, why wouldn't the two declarations be equivalent?

Answer 1

Yes, that makes no sense. You'll find the correct version in the Swift book:

In other words, the following two declarations are equivalent:

 var​ ​implicitlyUnwrappedString​: ​String​! ​var​ ​implicitlyUnwrappedString​: ​ImplicitlyUnwrappedOptional​<​String​> 

Excerpt From: Apple Inc. “The Swift Programming Language.” iBooks. https://itun.es/de/jEUH0.l