Understanding C++ Ranges and Filter View:

In this episode, Jesper continues his conversation with Nicolai Josuttis, diving into the controversial design of Filter View in C++20, C++23, and the upcoming C++26.

They explore how seemingly small design decisions in Ranges can break expectations around const-correctness, usability, and even safety and why fixing them is harder than it sounds once something becomes part of the standard.

Chapters:

00:00 Welcome

02:00 What’s broken in filter_view?

02:55 Constness, cache begin(), and unexpected side effects

06:11 Real-world dangers: reverse iteration & memory issues

09:09 Why the Standard Committee won’t fix it

11:12 The committee and expert bubbles

About the guest:

Nicolai Josuttis is well known in the C++ Community for writing with authority and speaking as an innovative presenter.

He is the author of C++20: The Complete Guide, C+++17: The Complete Guide, C++ Move Semantics, The C++ Standard Library, and a co-author of C++ Templates.

He has been an active member of the C++ standardization committee for more than 20 years.

Links:

• Link to episode 1 with Nicolai Josuttis
• CppCon 2024 presentation from Nicolai: Taming the C++ filter view in C++ Programming
• Nicolai Josuttis' 'The Filter View fiasco' paper
• Next episode with Nicolai Josuttis: TBA
• The complete interview with Nicolai, in 3 parts.
• All 'The Curious Developers' videos