> Has the C++ standardization committee given a rationale why a module definition does not automatically also create a namespace with the same name? That would seem such a useful feature.

I'm not sure what the official rationale is, but I feel that would cause great namespace pollution. Some companies use one namespace per "logical" unit of code (e.g. a subproject), not for each small piece of code (e.g. a small module implementing a couple of classes.