This module is a bridge between C code and Perl code (similar to Inline), the 'value' above is a C pointer to the structure that is tied, that I want to be able to stringify. 'xml_attribute_stash' is the Perl wrapper package for that particular class, which has 'use overload' with '""' and 'fallback' specified.

I found that I needed to use SvAMAGIC_on to enable overload on that tied C-structure so that the wrapper would see it as overloaded, but 'fallback' still isn't enabled. I'm guessing there's deeper magic to turn on fallback, since the perl wrapper isn't.