How Can I Determine the Type of an Object in C Polymorphic Code?

Type Identification in C

When dealing with polymorphic classes, it becomes essential to determine the type of an object passed to a function. Especially when overriding functions and accessing functions specific to inherited classes.

To ascertain the type of an object, C offers the powerful dynamic_cast functionality. This keyword performs a runtime check to cast a reference or pointer from one type to another.

The syntax for dynamic_cast is as follows:

TYPE& dynamic_cast<TYPE&>(object);
TYPE* dynamic_cast<TYPE*>(object);

Where TYPE represents the target type and object is the object to be casted.

If the cast is successful, a reference or pointer to the target type is returned. However, if the object cannot be cast to the target type, the following occurs:

• For reference casts, a bad_cast exception is thrown.
• For pointer casts, a NULL pointer is returned.

It's crucial to note that dynamic_cast requires the presence of at least one virtual function in the base class. This is because RTTI (Run-Time Type Information) relies on this mechanism to determine the type of an object.

The above is the detailed content of How Can I Determine the Type of an Object in C Polymorphic Code?. For more information, please follow other related articles on the PHP Chinese website!