Compile-time borrow checker with stateful metaprogramming

The first 2026 meetup of Haifa::C++ features a talk about a hot topic, which will help you deal with the cold winter! Alon Wolf will present his metaprogramming-based borrow checker, which can help you write safer C++ using compile-time checks.

Agenda:
17:30 - gathering at Tech&Talk
18:00 - Compile-time borrow checker with stateful metaprogramming by Alon Wolf
19:00 - wrap-up and mingling

Talk abstract:
This talk explores the implementation of a borrow checker in C++ using stateful template metaprogramming. We begin by defining what the borrow checker does and examining the various Rust implementations, such as Non-Lexical Lifetimes (NLL) and Polonius, along with their specific limitations. We then dive into the mechanics of stateful template metaprogramming to demonstrate how to enforce borrowing rules at compile-time.
The talk presents an implemention of a borrow checker in C++ and how to extend it to validate additional constraints. Finally, the talk will discuss how these techniques can be improved and simplified by the introduction of C++26 reflection.

Speaker bio:
Alon Wolf is a Senior Software Engineer at Medtronic specializing in 3D and computer graphics with a passion for high performance. He has developed many custom simulation and rendering engines for different platforms using modern C++. He also writes a C++ technical blog and participates in game jams.