I suppose you're talking about the thread on wxperl-users starting here? Quoting Mattia's reply with added emphasis:
At the moment there is partial support for handling exceptions in XS++: by default all exceptions are caught, and the XS wrapper die()s with a message. If the exception is derived from std::exception, the message includes the text of the what() method, otherwise a generic error message is thrown. Support for propagating the complete exception object to Perl is planned but not implemented yet.
If for any reason you don't want to use XS++, you need to put a try/catch block around the XS code and handle the exceptions manually
So while the mention of XS++ could have been more prominent, it was at least there. After all, you were asking this on the wxperl mailing list, so I guess Mattia assumed that you at least had a glance at the source code.
Either way, Extending and Embedding Perl couldn't have mentioned it. It's an old book. The first standalone release of ExtUtils::XSpp was just a year ago. There are not that many distributions on CPAN that use it and the tools that make it more convenient to use are still in their early stages. The slides of the talk that I pointed you at were from this year's YAPC::EU which ended less than two weeks ago. All things consdidered, it's not that surprising XS++ didn't pop up as the first thing when searching for XS and C++.
If you're using XS++ and like it, then there's something you can do about the visibility problem yourself: Blog about it. Tell people that and how you use it. Tell us how it helped you or, even better, how it could be more useful. We won't exactly send you away if you wanted to get involved with code either.