This was a lot to hold in your head at once.
Start by clarifying requirements and constraints, then design a class template with a pointer to the managed object and a separate control block for the reference count. Implement copy/move constructors, assignment operators, destructor, and key member functions like use_count and reset, ensuring exception safety and thread safety if needed.
Pro tip: Mention that you would use a separate control block to avoid overhead when multiple shared_ptrs share the same object, and discuss the importance of atomic operations for thread safety. Also, highlight the rule of five and how to handle self-assignment.
Ask about thread safety, custom deleters, weak pointer support, and whether it should be a drop-in replacement for std::shared_ptr. Confirm the expected interface and constraints.
Decide on storing a raw pointer to the object and a pointer to a control block containing the reference count (and possibly deleter). Consider using a separate control block to allow independent reference counting.
Write constructors, destructor, copy/move semantics, assignment operators, and member functions like use_count, reset, and operator overloads (*, ->). Ensure proper reference counting and exception safety.
Handle self-assignment, null pointers, and discuss atomic reference counting for thread safety. Mention potential optimizations like making the control block intrusive or using a single allocation.
Outline test cases: copying, moving, resetting, use_count checks, and destruction. Discuss how to verify no memory leaks and correct behavior in multithreaded scenarios.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.