型別會實作 From
和 Into
以利型別轉換作業執行:
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實作 From
時,Into
也會自動實作:
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Speaker Notes
This slide should take about 10 minutes.
- 這就是為什麼通常只需實作
From
,因為型別也會實作 Into
。
- 如要宣告函式引數輸入型別 (例如「任何可轉換成
String
的型別」),規則便會相反,此時請使用 Into
。 您的函式會接受實作 From
的型別,以及「僅」實作 Into
的型別。