id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
7303,XML Serialization - Skip/Ignore unexpected data.,anonymous,Robert Ramey,"Please find attached an extension to boost::serialization.  The purpose of this work is to add some support for forward compatibility of boost::serialization XML files; specifically the ability to skip/ignore unexpected data.

I would describe the patch as a ""first working version"", the tests all pass (gcc 4.6) with some expected failures (see below), but further work is required.  I guess I'm trying to gauge interest, get some feedback on the implementation, and get inspired enough to invest more time in it.

== Implementation ==

Two new archive types, `rapidxml_iarchive`, and `rapidxml_wiarchive`, have been created.  Their implementation is based on `xml_[w]iarchive` with the XML parsing provided by the rapidxml parser used in boost::property_tree.

This seemed the best approach to the problem as it avoided issues with `ungetc`.

Polymorphic versions of `rapidxml_[w]iarchive` have not been implemented.

== Test status ==

All tests are passing with the following caveats:

* Polymorphic rapidxml archives have not been implemented resulting in 6 tests failing to compile
* The following tests have had to be tweaked to accommodate rapidxml_[w]iarchive not ignoring element names
  * test_derived_class
  * test_recursion
  * test_nvp 
  * test_non_default_ctor2
  * test_diamond
  * test_diamond_complex

== Notes and further work ==

The current implementation is a ""first working version"" and requires some polishing.  There are a number of things that require further investigation, broadly speaking they can be categorized as:

* Better reuse
  * Factor out a base class (templated on char type) for `rapidxml_iarchive` and `rapidxml_wiarchive`
  * Some code could be shared between `rapidxml_[w]iarchive` and `xml_[w]iarchive`
    * See `[rapid]xml_iarchive::load(std::wstring&)`
    * See `[rapid]xml_wiarchive::load(std::string&)`
* Better error handling
* Flag support
  * Currently there are no plans to support any kind of flags/alternative behaviour so the existing flag code may need to be removed
* Miscellany
  * Go through comments to see what's still relevant
  * Replace history map with vector
",Feature Requests,new,To Be Determined,serialization,Boost 1.51.0,Not Applicable,,,