協議內的Typealias

Question

我的協議中有一個typealias。我必須將typealias添加到符合類型還是有其他選擇？我的目標是聲明一次typealias。

protocol SomeProtocol { 
    associatedtype T 
    typealias Closure = (T) -> Void 
    var blocks: [Closure] { get set } 
} 

struct SomeStruct<T>: SomeProtocol { 
    typealias Closure = (T) -> Void // <- do I have to add this? 
    var blocks: [Closure] 
} 

僅供參考。我只是尋找一個更簡單的實現的typealias。

Answer 1

你不一定需要在struct的typealias - 它可以推斷出：

protocol SomeProtocol { 
    associatedtype T 
    typealias Closure = (T) -> Void 
    var blocks: [Closure] { get set } 
} 

struct SomeStruct<T>: SomeProtocol { 
    var blocks: [(T) -> Void] 
} 

let someStruct = SomeStruct<Int>(blocks: [{someInt in print(someInt)}]) 
someStruct.blocks[0](123)