Problem Description

Implement a minimal C++ reference-counted smart pointer, SharedPtr<T>, analogous to std::shared_ptr.

Requirements

• The SharedPtr<T> class template must manage a heap-allocated T*.
• Adhere to the Resource Acquisition Is Initialization (RAII) principle: the managed object must be deleted exactly once when the last SharedPtr instance owning it is destroyed.
• The implementation must support the following member functions and operators:
  • Default constructor (initializes to a null pointer).
  • Constructor from a raw pointer T*.
  • Destructor.
  • Copy constructor and copy assignment operator (must correctly increase the reference count).
  • Move constructor and move assignment operator (must transfer ownership, leaving the source SharedPtr in a null state).
  • Dereference operator: T& operator*().
  • Member access operator: T* operator->().
  • Raw pointer accessor: T* get() const.
  • Reference count accessor: size_t use_count() const.
  • Reset function: void reset(T* p = nullptr).
• The implementation must correctly handle self-assignment and prevent memory leaks or double-free issues.

Scope & Assumptions

• Thread-safety may be ignored unless explicitly chosen for implementation.