After I gave you in my last post (C++20: Coroutines - A First Overview) the first impression of coroutines, I want to provide today more details. Once more, we get in C++20 not coroutines but a framework for building coroutines. 

I'm looking for proofreaders for my new book "C++ Core Guidelines". The crucial idea of the book is to put the precious ideas of the C++ Core Guidelines into a readable book for the big audience. This book includes more than a hundred examples to study the theory in praxis.

C++20 provides four features that change the way we think about and write modern C++: concepts, the ranges library, coroutines, and modules. I already wrote a few posts to concepts and the ranges library. Let's have a closer look at coroutines. 

Image by Peggy und Marco Lachmann-Anke from Pixabay

I want to say a few personal words due to exceptional circumstances.

Today, I finish my experiment writing beloved Python functions in C++. So far, I implemented the Python functions filter, range, and xrange. Today, I have a closer look at the map function and combine the functions map and filter into one function.

In my last post C++20: Pythonic with the Ranges Library, I started my experiment to implement the beloved Python functions range and filter in C++. Due to two very interesting comments to my last post, I revisit the function range. 

Today, I start an experiment. I want to implement beloved functions in Python in C++ using the ranges library. I'm curious about how it goes.

My last post C++20: The Ranges Library, gave you the first impression of the ranges library. Today's post is about functional patterns: function composition and lazy evaluation. They become first-class citizens in C++20.

Thanks to the ranges library in C++20, working with the Standard Template Library (STL) will become much more comfortable and powerful. The algorithms of the ranges library are lazy, can work directly on the container and can easily be composed. To make it short: The comfort and the power of the ranges library are due to its functional ideas. Let me show you what that means.

Let me conclude my series to concepts with this meta-post. Are concepts an evolution or a revolution in C++? The answer to this question bothered me quite a time.