[boost] Evaluation of the PropertyTree library

I am currently using the PropertyTree library and I think it's both useful and easy to use. I haven't looked too much into the implementation, but I wanted to mention that although the library enables the use of wchar_t for properties and their values, it does not do so for file names (xml_read for instance takes a "std::string" for a filename). There are, however, people amongst us that work on operating systems with Unicode-enabled file systems. This should be supported by the library. Sincerely, Christian Strömsdörfer