CppCon 2018

The last time the keyword `concept` appeared in the C++ Standard's working draft was July 2009, two years before the release of C++11. Now, in September 2018, two years before the expected release of C++20, the working draft once again contains something called "Concepts" — something very different from what was there before, and — so far — much more conservative than the Concepts TS (formerly known as "Concepts Lite").
What should the forward-looking C++ programmer do and know about Concepts in C++2a? Arthur will attempt to puzzle it all out. What is a "Concept" and why should we care? What is the current syntax for defining and using concepts? What compilers support C++2a concepts syntax today, and how do I enable it? How does it affect name-mangling? What are "atomic constraints," "disjunctive clauses," and "subsumption"? What good are value concepts and template concepts? What is the difference between a "requires clause" and a "Requires element"? What is this "terse syntax" we've been hearing about, and why is it controversial? What is "Giraffe_case" and should I use it? Can I use the "requires" keyword without Concepts?
This material will be presented from an outsider's perspective, which means you can expect Arthur to say at least a few wrong things; and the shelf life of this material will be short, as C++2a Concepts are very much in flux right now. Still, if you want to get caught up on (or in) the Concepts discussion, this might be the place for you.