有没有办法在Delphi中基于不同的Result类型来重载一个函数？ [英] Is there a way to overload a function based on different Result type in Delphi?

问题描述

功能按返回类型重载？

对返回类型的函数重载的理性有一个非常详细的答案，从我可以看到，Delphi不允许这样做，但是是否有任何解决方法来重载基于Delphi中不同返回类型的函数？

has a very detailed answer on the rational on function overloading by return type, and from what I can see Delphi does not allow this, but are there any workarounds to overload a function based on different return type in Delphi?

推荐答案

记录的隐式和显式转换操作符允许以返回类型重载：即正在转换为的类型：

The implicit and explicit conversion operators for records permit overloading by return type: namely, the type being converted to:

type
  TFoo = record
    class operator Implicit(const AFoo: TFoo): Integer;
    class operator Implicit(const AFoo: TFoo): string;
  end;

根据上下文，使用类型为 TFoo 将调用适当的隐式转换。如果尝试使用类型为 TFoo 的值作为重载例程的参数，该例程可以在该位置使用整数或字符串，则会发生重载错误：

Depending on the context, using a value of type TFoo will call the appropriate implicit conversion. If trying to use a value of type TFoo as an argument to an overloaded routine that can take either Integer or string in that position, an overload error will occur:

test.pas(33) Error: E2251 Ambiguous overloaded call to 'Q'
 + Test.pas(19) Related method: procedure Q(Integer);
 + Test.pas(24) Related method: procedure Q(const string);

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