What are some common iterator design patterns in C++ STL?

What are some common iterator design patterns in C++ STL?

In C++, the Standard Template Library (STL) provides several iterator design patterns, including input iterators, output iterators, forward iterators, bidirectional iterators, and random access iterators. Each serves different purposes and has unique characteristics.

Can you explain the difference between a forward iterator and a bidirectional iterator?

Sure! A forward iterator allows you to traverse a container in one direction, from the beginning to the end. In contrast, a bidirectional iterator can traverse both forwards and backwards, allowing you to move to the previous element as well.

What are some use cases for random access iterators?

Random access iterators are useful when you need to access elements at arbitrary positions in a container, like in arrays or vectors. They allow for efficient element access and manipulation, similar to pointer arithmetic.

How do I implement a custom iterator in C++?

To implement a custom iterator in C++, you need to define a class that overloads the necessary operators (like ++, *, and !=). You also need to define the iterator's behavior based on the container it will iterate over.