#include <memory>
std::shared_ptr<int> foo = std::make_shared<int> (10);
shared_ptr<T> p; ---> T * p; : nothing is const
const shared_ptr<T> p; ---> T * const p; : p is const
shared_ptr<const T> p; ---> const T * p; <=> T const * p; : *p is const
const shared_ptr<const T> p; ---> const T * const p; <=> T const * const p; : p and *p are const.