C++ Concepts: Pros/Cons and Examples

C++20 concepts give us a brand new way to specify how our generic libraries and algorithms should be used and allow library users to better understand what is expected of them. However, concepts didn't rise from chaos, and before their adoption C++ library authors had other mechanisms to meet that goal.

In this talk, Roi Barkan will briefly discuss concepts, and focus on their pros and cons compared to more mature mechanisms. Special attention will be given to the 'semantic' vs. 'syntactic' nature of concepts, and Roi will try to give motivating examples of semantic-only concepts. He will explore best practices, and show potential pitfalls in various approaches to the challenge of defining interactions between generic code authors and users.