Which we seldom due on most C++ projects, we rather rely on binary libraries and build only our own code.
Also when comparing with Delphi, Ada, D, or even Haskell or OCaml, it isn't that great.
You might feel like pointing out that Haskell or OCaml can be even slower, which is true, however they package multiple toolchains and a REPL, and as of today Rust still isn't as flexible in having multiple toolchains for different purposes.