Comment by taylorallred

These languages do more at compile time, yes. However, I learned from Ryan's discord server that he did a unity build in a C++ codebase and got similar results (just a few seconds slower than the C code). Also, you could see in the article that most of the time was being spent in LLVM and linking. With a unity build, you nearly cut out link step entirely. Rust and Swift do some sophisticated things (hinley-milner, generics, etc.) but I have my doubts that those things cause the most slowdown.