如何在XML中格式化Google Protocol Buffers对象并从XML进行解析

I'm going to pass GPB objects over the wire but in the local application I need to save them locally in XML (customer demands XML, no editing tool, don't ask me why) so the customer can edit the XML (which brings me to the other part of my question - parsing GPB from XML). Is anyone aware of a framework which does this? I need this code in C++ on Windows.I'm going to pass GPB objects over the wire but