Jasper Blues Jasper Blues - 11 months ago 36
Swift Question

Swift : Define a closure compatible with Objective-C block

I tried to declare a closure matching the following Objective-C block:

typedef void(^TyphoonDefinitionBlock)(TyphoonDefinition *definition);

like this:

var config: TyphoonDefinitionBlock = { (definition: TyphoonDefinition) in
definition.injectProperty("quest", with: nil)

. . . and got the following error. (see image).

enter image description here

What's the correct way to do this?


You need to declare definition as an ImplicitlyUnwrappedOptional (TyphoonDefinition!) because in objective-C it is a pointer that can be nil.

Normal variables (and constants) in swift cannot be nil. They must contain a value.