It would be nice if there were a way to send the PDF output from QPrinter to memory instead of a file, something like:

QPrinter.setOutputDevice(QIODevice* device)

Sometimes there is a need to generate PDFs with sensitive (secret) content, and it would be preferable not having to write these to disk at all.
Also there could be a performance gain if the content could be retrieved directly from the buffer when saving the PDF is not needed or wanted.