如何检查对象的类型是否是 C++ 中的特定子类?

问题描述

我正在考虑使用 typeid() 但我不知道如何询问该类型是否是另一个类的子类(顺便说一下，它是抽象的)

I was thinking along the lines of using typeid() but I don't know how to ask if that type is a subclass of another class (which, by the way, is abstract)

推荐答案

你真的不应该.如果您的程序需要知道一个对象是什么类，这通常表明存在设计缺陷.看看你是否可以使用虚函数获得你想要的行为.此外，有关您正在尝试执行的操作的更多信息会有所帮助.

You really shouldn't. If your program needs to know what class an object is, that usually indicates a design flaw. See if you can get the behavior you want using virtual functions. Also, more information about what you are trying to do would help.

我假设你有这样的情况:

I am assuming you have a situation like this:

class Base;
class A : public Base {...};
class B : public Base {...};

void foo(Base *p)
{
  if(/* p is A */) /* do X */
  else /* do Y */
}

如果这是你所拥有的，那么尝试做这样的事情:

If this is what you have, then try to do something like this:

class Base
{
  virtual void bar() = 0;
};

class A : public Base
{
  void bar() {/* do X *