[Compiler]Enable Run-Time Type Information

[Kulagin]

@ddbrown30

Without knowing what your code is trying to do or why, a simple and easy solution to this would be to create an enum with a value mapping to each of your class types. Then, add a virtual function to your base class that’s something like GetClassType. Then, in each of the child classes, have them implement that function and return their corresponding enum.

This solution is something you want to show to your students and tell them to never ever use it in their code. There are better solutions both: clean-code-wise and performance-wise:

Rabobank IT | Clean coding | Livestream 2019 Uncle Bob | 7 February 2019

Breaking Dependencies: The SOLID Principles - Klaus Iglberger - CppCon 2020

Klaus Iglberger - Keynote: Embrace No-Paradigm Programming!

It was probably Ok to use enum solution in some language in 1972 when there simply was no alternatives in your language back then. It is not Ok to use it in modern languages: in C++ case it’s since the moment it was introduced in 1979.

@ddbrown30

You could also accomplish this without the enum by using individual functions i.e IsClassA(), IsClassB(), etc. This can make your code messy very quickly, but it’s also more flexible. For instance, you could support ClassC which is a child of ClassB which is a child of ClassA, and you would be able to call IsClassA(), IsClassB(), and IsClassC() and they would all return true.

This one has all the problems the first one has. Instead of a switch statement you have a bunch of if statements everywhere your code uses this hierarchy.