Rust is going down the path where recompilation is done on a finer granularity than files. I was objecting to setting that as the bar to meet for incremental compilation. It's technically impressive, but it will only be a win if the average compilation unit takes a noticeable amount of time to compile (this was rarely the case with Delphi). It may well be the case for Rust+LLVM.
Fair. I think Delphi counts, and I don't think that was the bar being set (but it's easy to see how it could be read that way). The C++ header file model is quite different in the amount of burden placed on the programmer over the Delphi use-statement model.
He also says that merely using the separate files to deduce this (which the parent says is what Delphi does) is not incremental compilation.