c ++从派生类指针获取基类对象？

Question

假设我有Derived * derivedPtr;
我想要来自derivedPtr的Base baseObject;

Base baseObject = * derivedPtr;会使用适当的Base类成员变量创建baseObject吗？

谢谢

Answer 1

是Object Slicing

Derived* obj = new Derived;
base objOne = (*obj) ;  // Object slicing. Coping only the  Base class sub-object
                        // that was constructed by eariler statement.

Answer 2

您可以使用动态投射来完成此任务。

e.g。

Base* baseObject = dynamic_cast<Base*>(derivedPtr);

http://www.cplusplus.com/doc/tutorial/typecasting/

Answer 3

是。这实际上被称为“切片”，因为你只是从派生类中切掉一切。