I have never made an extension, so I cant answer your question out right.

I played around with your code, and I read perlman:perlxs and perlman:perlxstut and I did not get very far with C++ coding. It seems that it is all written in C, and there are little or no examples for C++.

I looked in Advanced Perl Programming and that only briefly mentions C++ also. But the author Sriram Srinivasan mentions other resources on CPAN by Dean Roehrich. Dean has code and extension examples in two cookbooks: CookBookA and CookBookB which you can get here I have not had the chance to look at them but the readme looked promising.

Good luck. I will post more if I find anything else out.