what are the different ways to achieve polymorphism in c++

Question

I know there are a few different ways to achieve polymorphism in c++.

I know of 3 ways to do this:

by using inheritance (through the use of a pointer to a base class)
by using virtual function
by using abstract classes

During a technical discussion on the topic I was told I am missing something and was left hanging...hence I asked the question here.

Is there another way in c++ to to this or is something I said wrong?

those aren't really different ways. in the end, you will use a pointer to a base class... — Karoly Horvath, Feb 18 '14 at 11:04
you only talked runtime polymorphism, maybe we can take compile time polymorphism in count, like template and funciton overloading — michaeltang, Feb 18 '14 at 11:06
Besides inheritance and templates, there's plain function pointers. — eerorika, Feb 18 '14 at 11:08
follow this link [link](http://stackoverflow.com/questions/5854581/polymorphism-in-c) may be you get your answer. — Rivan, Feb 18 '14 at 11:11
Please Use this [Link](http://en.wikipedia.org/wiki/Polymorphism_(computer_science)) — A B, Feb 18 '14 at 11:12
Besides run time polymorphism,you can achieve compile time polymorphism through operator and function overloading. — Subhajit, Feb 18 '14 at 11:19
@Subhajit I suspect that the answer they were looking for was templates (but operator and function overloading is also a good answer). — James Kanze, Feb 18 '14 at 11:26

score 2 · Accepted Answer · answered Feb 18 '14 at 11:25

Your three ways are really just one: whether the base class is abstract is an implementation detail; you need virtual functions, which can be overridden in a derived class.

Other than that: both function overloading and templates provide a form of polymorphism as well, although it is resolved at compile time, and not run time. For that matter, you can define a class in a header file, and provide several different implementations for it, depending on compile time switches; that's also a form of polymorphism. (This is often done for system dependent code. The polymorphism is resolved as a function of the system you're compiling for.)

score 0 · Answer 2 · answered Feb 18 '14 at 11:40

0

I think your discussion was related to different types of polymorphism.

Compile time polymorphism - Ex: Function Overloading, Operator Overloading.
Run time polymorphism - Ex: Inheritance + virtual functions + base class pointer.

answered Feb 18 '14 at 11:40

rockoder

747
10
22

what are the different ways to achieve polymorphism in c++

2 Answers2