We have working struct signature for few nsvalue methods. I will do a more tests on other classes. It seems that case when we need to call objc_msgSeng or objc_msgSend_stret when we need to return structure depends on architecture, so I write case for x86_64 architecture, and I put some docs on that line, and some resources about x86_64. It will be needed to implements other cases (PowerPC and IA-32 which are supported by apple)