CppCon 2018

Compile-time programming and reflection have been getting a lot of attention recently. Indeed, from Herb Sutter's well-known Metaclasses proposal to the newly created Reflection TS, a lot of effort is being put into solving the general problem of programmatic code generation and program introspection. More recently, the C++ Standards Committee has also been evaluating and adopting proposals that vastly expand the realm of constructs available at compile-time, in constexpr functions: new-expressions, try-catch blocks, virtual functions, some standard containers, and more.

For most people, it is unclear how all these features, whether exploratory or voted into the Draft International Standard, relate together. Without being active in the Committee, it can be difficult to see the big picture, the unifying vision driving all these changes. Fortunately, there is one, and this is what this talk is about.

We will go over these features and explain how they might interact with each other by boiling them down to their essential parts. We will present how different use cases for compile-time programming will be solved in C++20, and how even more use cases can be unlocked in the future. Attendees will leave this talk with an understanding of the improvements to constexpr planned for C++20, of what's needed to unlock more advanced use cases and an unifying vision for how to get there.