CppCon 2026

A chess engine must search millions of positions per second. Move generation is often a bottleneck. Generating moves for knights, kings, and pawns are computationally cheap (~1 nanosecond). However, rooks, bishops, and queens (aka "sliding pieces") present a unique challenge: their movement depends on the placement of other pieces. This makes on-demand generation too slow (20+ nanoseconds) and naively-implemented lookup tables impractical (requiring zettabytes of RAM).

We will start by reviewing the core data structures in a chess engine and the logic behind move generation. Then, we will explore "magic bitboards", a perfect hashing technique that enables sliding piece move generation in ~1 nanosecond. We will look at how to implement this in modern C++, comparing hardware-specific instructions like PEXT (Parallel Bits Extract) against a portable software approach. Finally, we will discuss the practical challenges of generating the data structures required for magic bitboards, including the limitations of consteval and how to integrate build-time table generation into the build process using Bazel.

To ground these concepts, we will be referencing implementation details and code from my C++ chess engine, FollyChess.

Building on the recent work of improving the quality of Sea of Thieves' codebase by upgrading from C++14 to C++20, this talk will focus on the work that has went into enabling warnings as errors on the game, and more.

Rare will discuss the motivations behind wanting to crank up the warning level, and to flick the "warnings as errors" switch after 10 years of development in their multi-million line Unreal Engine code base.

What were the challenges? How much effort did it take? Was it worth it? Did we find any bugs? Did we stop at just "/W4 /WX"? What warnings did we find the most useful? What warnings were deemed unhelpful? All of these questions and probably more will be answered throughout this session.

Scripting in a C++ game engine should not cost you the engine's native performance. This talk shows how C++26 static reflection and std::meta::substitute in particular can lift a scripting language's bytecode into C++ template structures that the compiler optimizes away entirely, collapsing the interpreter dispatch loop into the same machine code you'd write by hand. Scripting languages like AngelScript and Lua are invaluable in C++ engines: they give designers a fast iteration loop without rebuilding the engine. But they come with a paradox. The engine you chose for raw performance now spends cycles on every frame interpreting a slower language, juggling a software stack and checking types at runtime. We will walk through the technique step by step, starting from a plain bytecode interpreter and ending at a fully reflected program where a scripted sum(0..10) compiles to mov eax, 45; ret. Along the way you'll learn the core C++26 reflection primitives (^^, [: :], std::meta::substitute), how to assemble bytecode into structural templates like block<> and loop<>, and how these techniques generalize to embedding any stack or register based scripting language in your engine with zero runtime overhead.