Please don't thoughtlessly replace pointers with shared_ptrs in an attempt to prevent memory leaks; shared_ptrs are not a panacea nor are they without costs:
-a circular linked structure of shared_ptrs will cause a memory leak (you'll need some logical complication to break the circle, e.g. using a weak_ptr)
-"shared ownership objects" tend to stay "live" for longer than scoped objects (thus causing higher average resource usage)
-shared pointers in a multi-threaded environment can be expensive (because of the need to avoid data races on the use count)
-a destructor for a shared object does not execute at a predictable time, and the algorithms/logic for the update of any shared object is easier to get wrong than for an object that's not shared
