IMO what is needed is a preprocessor with reference semantics that are conformable to the modern notion of modules. I.e. a preprocessor that thinks that a refer

IMO what is needed is a preprocessor with reference semantics that are conformable to the modern notion of modules. I.e. a preprocessor that thinks that a reference is defined when it's defined in a module included by this one, instead of "before this point in a translation unit." This way it's adequate to include a list of defined symbols in a pre-compiled header, and reuse them when including that module to some other module.