Swift 3中的泛型類別別名？

Question

我們如何可以聲明泛型類型別名在迅速3.

我嘗試以下操作：

typealias DictionaryOfStrings<T> = Dictionary<T, String> 

而產生錯誤：

error: type 'T' does not conform to protocol 'Hashable'

Answer 1

typealias DictionaryOfStrings<T: Hashable> = Dictionary<T, String> 

var dict = DictionaryOfStrings<Int>() 

dict[1] = "One" 
dict[2] = "Two"