How to define stack size for particular thread with C++ boost library?

I need to increase the stack size of a boost::thread object. The thread's task is to store a large set 3D points, which is implemented recursively and thus needs quite some memory space on the stack.

int main(int argc, char* argv[]) {
    Flashlight *flashlight = new Flashlight();
    flashlight->thread_group = new boost::thread_group();
    boost::thread::attributes attrs;
    attrs.set_stack_size(16*1024*1024);
    flashlight->orbslam_thread = new boost::thread(attrs, boost::bind(&Flashlight::orbslam_loop, flashlight));
    flashlight->thread_group->add_thread(flashlight->orbslam_thread);
    // initializing some more threads ...
    flashlight->thread_group->join_all();
    return 0;
}

A.) Did I increase the thread's stack size to 16MB correctly in the code listed above?

B.) Is it possible to read the attributes, in particular the current stack size, of a boost::thread object somehow?