I think I'm catching on. With a '#include', you give a file name. With an 'import', you give a module name, which doesn't necessarily map to a file name.

So the problem could be solved by saying 'import foobar;' maps to a file (on a search path, maybe) named exactly "foobar". But then we need to work out how subdirectories and module names map to each other. How do you import "foo/bar.ixx"? "foo.bar"? "<foo/bar>"?

Though all that seems technically solvable to me. Maybe there's just difficulty in designing this in the context of a committee.