Is there a way to increase the efficiency of shared_ptr by storing the reference count inside the controlled object?

Question

This is becoming a common pattern in my code, for when I need to manage an object that needs to be noncopyable because either A. it is \"heavy\" or B. it is an operating sys

Answer 1

A partial solution is to use make_shared to create your shared_ptrs. For example,

auto my_thing = std::make_shared();

instead of

auto my_thing = std::shared_ptr(new Thing);

It's still non-intrusive, so nothing else needs to change. Good implementations of make_shared combine the memory allocation for the reference count and the object itself. That saves a memory allocation and keeps the count close to the object for better locality. It's not quite as efficient as something like boost:intrusive_ptr, but it's worth considering.