Hmm. How would you do away with header files in a simple way if you wanted something similarly-scoped to C? Have the compiler vacuum in every source file at onc

Hmm. How would you do away with header files in a simple way if you wanted something similarly-scoped to C? Have the compiler vacuum in every source file at once to pick up all references, then discard via dead code elimination? That'd kill incremental compilation :/ (I'm genuinely curious about the answer to this question - I'm also looking for something similar to C)