C# · 12月 23, 2021

C#编译器如何处理重载显式转换运算符?

编译器应该翻译这段代码: public static explicit operator Int64(MyNumber n){ return n.ToInteger();}public static explicit operator Double(MyNumber n){ return n.ToDouble();}

两种方法具有相同的名称和签名,但只有它们的返回类型不同,例如

public static Int64 ExplicitCast(MyNumber n)…public static Double ExplicitCast(MyNumber n)…

但是,我们不允许只有返回类型的方法.窗帘后面会发生什么?

解决方法 从技术上讲,CLS(公共语言规范,指定所有.NET语言应支持的.NET虚拟机的子部分的规范)表示显式强制转换方法的名称应为op_Explicit(参见例如 http://goo.gl/wn8dHq).

您不能拥有多个具有相同名称且只有不同返回类型的方法的限制是C#的限制. IL语言(即.NET虚拟机的语言)没有此限制.

参见例如:https://stackoverflow.com/a/442100/613130

Some languages (such as MSIL),however,do allow overloading by return type. They too face the above difficulty of course,but they have workarounds,for which you’ll have to consult their documentation.

和https://blogs.msdn.microsoft.com/abhinaba/2005/10/07/c-cil-supports-overloading-by-return-type/

However,CIL does support overloading methods by return types,even though C#,VB does not . To implement convertion operator overloading C# compiler uses this feature (I kNow of one usage and I’m sure that there are more