The whole thing compiles with 2 warnings. Incredible codebase. John Carmack definitely was/is on a different level.

Back when I was making videogames I followed a similar philosophy. No warnings (but in an orders-of-magnitude smaller and less complex codebase). Crash on failed asserts, used liberally, in debug builds. Not sure why but it seems that gamedev doesn't do this kind of rigorous engineering in general (or at least it didn't back then -- and admittedly I never worked in a big studio).