For where I'm at currently you don't need that much. This is it at the moment https://github.com/k0nserv/rusttracer/blob/master/src/math.r.... I learned about rust macros, operator overloading, traits, derive, tests, the difference between copy and clone in the process. It was a good first step in rust for sure. It's also one of those things that lends them self to TDD very nicely and that cuts down the need to debug anything.