Extracting all symbols from namespace

Hi everyone,

I noticed that there's a refactoring function to safe-delete a namespace, but I can't quite seem to make sense of it. I expected it to delete the namespace enclosure "namespace Foo{ [...] }" in all project files, leaving the contents alone and so effectively moving them into the parent namespace. But instead, it only modified the current file, deleting the namespace enclosure as well as everything in it.

Hence my question: Is there a refactoring function that does what I'm looking for? Or maybe an extension?