Swiftを使用して辞書の配列を拡張する2.2

Question

この拡張機能を制約する正しい方法は何ですか？私の試練は成功しなかった。例えば

：

extension CollectionType where Generator.Element: [T.Key:Self.Value], T: DictionaryLiteralConvertible, T.Key: StringLiteralConvertible, T.Value: Encodable { 

Answer 1

Xcodeの8ベータ•スウィフト3

protocol Encodable { 
    var hashValue: Int { get } 
} 
extension Int: Encodable { } 

extension Collection where Iterator.Element == [String: Encodable] { 
    var total: Int { 
     return reduce(0) {$0 + $1.values.reduce(0) {$0 + $1.hashValue}} 
    } 
} 

let dictionaries:[[String: Encodable]] = [["One":1],["Two":2],["Three":3, "Four":4]] 

dictionaries.total // 10 

---

のXcode 7.3.1•スウィフト2.2.1

protocol Encodable { 
    var hashValue: Int { get } 
} 

extension Int: Encodable { } 

extension CollectionType where Generator.Element == [String: Encodable] { 
    var total: Int { 
     return reduce(0) {$0 + $1.values.reduce(0) {$0 + $1.hashValue}} 
    } 
} 

let dictionaries:[[String: Encodable]] = [["One":1],["Two":2],["Three":3, "Four":4]] 

dictionaries.total // 10