Module globals in a C++ extension

Hi again, could someone post some info about writing extensions in C++ with object as a module global? (that is, regardless of the used MPM (or something else), make some object instance common for all running instances of the same extension) For one, I wonder how many more extensions in pecl are written in C++, not counting SCA_SDO? (looking for real-world examples!) And .. may I? Is that reasonably easy to use CMake instead of auto*hell to manage extension build process? Or why not?