Which parts of what? Modern game engines? Nearly all of it, minus often gameplay scripting. In the hypothetical C++/Rust fusion engine? Whatever hasn't been re

Which parts of what? Modern game engines? Nearly all of it, minus often gameplay scripting. In the hypothetical C++/Rust fusion engine? Whatever hasn't been rewritten yet in Rust, and specifically things that interop with other C++ libraries will remain in C++ for longer times. Edit: Ohh Servo? Similarly, things that haven't been rewritten yet, specifically javascript interpertation/compiliation. AFAIK Servo is focusing on rewriting layout.