C++20 introduced a new feature known as ranges and views, which aim to simplify and improve the way we work with ranges of data in C++. In this article, we will take a deep dive into the internal implementation of ranges and views to understand how they abstract the STL data structures.
First, let's start by looking at ranges and views in more detail. A range is a sequence of elements, while a view is a range that provides a read-only access to the underlying data. Ranges and views are designed to be lightweight and easy to use, making them a great choice for many types of applications.
One of the key features of ranges and views is their ability to abstract the underlying data structure. This means that you can use the same range or view to work with different types of data, such as an array, a vector, or even a custom container. This is achieved by using a set of iterators and a set of functions that operate on these iterators.
The iterators used by ranges and views are known as range iterators, and they are designed to be more powerful and flexible than the standard STL iterators. They are also designed to be more efficient, as they do not require the use of dynamic memory allocation.
In terms of functions, ranges and views provide a set of algorithms that can be used to perform various operations on the data, such as filtering, sorting, and transforming. These algorithms are designed to be easy to use and efficient, making them a great choice for many types of applications.
One important thing to note about ranges and views is that they are not a replacement for the STL. Instead, they are designed to work alongside the STL and to complement it. This means that you can use ranges and views in combination with the STL to achieve even more powerful and efficient code.
In terms of internal implementation, ranges and views use a technique called "tagged unions" to store the underlying data. This allows the range or view to be lightweight and efficient, while still providing a powerful and flexible interface.
Another interesting feature of ranges and views is that they are designed to be composable. This means that you can combine multiple ranges and views together to create more complex and powerful operations. For example, you can use a filter view to filter a range, and then use a transform view to transform the filtered data.
In conclusion, ranges and views are a powerful and flexible feature in C++20 that provide a new way to work with ranges of data. They are lightweight and easy to use, and they abstract the underlying data structure, making them a great choice for many types of applications. Their internal implementation uses "tagged unions" for storage and composability for creating complex operations, making them efficient and powerful. They are designed to work alongside the STL, allowing for even more powerful and efficient code.