Auto-Assigning to Modules

Is it possible to automatically assign stuff (files, namespaces,
classes, macros, functions, whatever) to modules without having to
specify this in each source file explicitly?

For example, if a particular directory is assigned to a module, is it
possible to have all the files and subdirectories in that directory to
also be assigned to that module by default?

Likewise, if a particular file is assigned to a module, is it possible
to have all the classes and structures and other stuff defined therein
to also be assigned to that module by default?

Alternatively, if a particular namespace is assigned to a module, is it
possible to automatically have all the stuff in that namespace to also
be assigned to that module by default?

So far I haven't had any success with that.

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