C++26 has brought big advances, especially with reflection making its way into the working draft, but one long-standing challenge remains: supporting richer class types as constant template parameters. Although the language solution isn’t here yet, we can get surprisingly far with a library approach that uses reflection and static objects to extend what’s possible today.

A Library Approach to Constant Template Parameters

by Barry Revzin

From the article:

This library achieves two things.

First, it is just, in general, very useful. I’m hoping to make it more of a Real Library™️ once Reflection gets implemented in more than just the Bloomberg fork of Clang that Dan Katz implemented.

Second, I think it demonstrates the power of Reflection. There are so many problems that were not possible in C++23 that become solvable in C++26. We’re going to spend the next several years discovering more of those, and that makes it a pretty exciting time for C++.