Login | Register   
RSS Feed
Download our iPhone app
Browse DevX
Sign up for e-mail newsletters from DevX

By submitting your information, you agree that devx.com may send you DevX offers via email, phone and text message, as well as email offers about other products and services that DevX believes may be of interest to you. DevX will process your information in accordance with the Quinstreet Privacy Policy.

Tip of the Day
Language: C++
Expertise: All
May 15, 2000



Building the Right Environment to Support AI, Machine Learning and Deep Learning

Using dynamic_cast

You can apply operator dynamic_cast only to polymorphic objects (a polymorphic object is one that has at least one virtual member function). This is a requirement of the C++ standard. There are two reasons for this restriction. In order to perform a dynamic cast, the implementation needs to access the runtime type information of the object to which dynamic_cast is applied. This information is retrieved through the object's vptr, and as you probably know, only polymorphic objects have a vptr. However, there's another reason for this restriction—a philosophical one: the type of a non-polymorphic object is static and can be determined at compile time. Therefore, there's not much point in generating runtime type information for non-polymorphic objects in the first place. Note also that some compilers require that you switch on a compiler option in order to enable RTTI support.
Danny Kalev
Comment and Contribute






(Maximum characters: 1200). You have 1200 characters left.



Thanks for your registration, follow us on our social networks to keep up-to-date