It has no effect on the lifetime of the object, but it can affect the lifetime of the allocation. The reason is that weak_ptr needs the control block, which mak

It has no effect on the lifetime of the object, but it can affect the lifetime of the allocation. The reason is that weak_ptr needs the control block, which make_shared bundles into the same allocation as the object for optimization reasons. Quoting cppreference [0]: If any std::weak_ptr references the control block created by std::make_shared after the lifetime of all shared owners ended, the memory occupied by T persists until all weak owners get destroyed as well, which may be undesirable if sizeof(T) is large. [0] https://en.cppreference.com/w/cpp/memory/shared_ptr/make_shared.html https://en.cppreference.com/w/cpp/memory/shared_ptr/make_sha...