C++17 STL Cookbook

How to do it...

In this recipe, we will implement our own iterator class, and then, we will iterate through it:

1. First, we include the header, which enables us to print to the terminal:

      #include <iostream>

2. Our iterator class will be called num_iterator:

      class num_iterator {

3. Its only data member is an integer. That integer is used for counting. The constructor is for initializing it. It is generally a good form to make constructors explicit, which create a type from another type to avoid accidental implicit conversion. Note that we also provide a default value for position. This makes the instances of the num_iterator class default-constructible. Although we will not use the default constructor in the whole recipe, this is really important ...