[xml] Tool to help fill in structures from XML

[David Hagood <wowbagger sktc net>]

Does anybody know of a good tool which takes the drudgery out of reading
XML into structures?

Specifically, what I'd like would be a tool that allows me to describe an
XML grammar (e.g. via RelaxNG) and a structure layout, and then generate
tables or code that would read an XML file and store the incoming elements
into objects in C++.

e.g. given

struct some_struct
{
  int a;
  int b:4;
  enum {larry,moe,curly} stooge;
};

parse
<some_struct a="5">
  <b>4</b>
  <stooge which="moe"/>
</some_struct>

and give me a filled-in some_struct object. Obviously, there would have to
be some other file which mapped the XML entities into the structure (and
vis-versa) - ideally some XML file which, when chewed upon by the proper
tool, would spit out C++ code and a RelaxNG schema.

Does anybody know of such a tool?