How is the guarantee of object uniqueness implemented using std::unique_ptr in C++?

std::unique_ptr in C++ implements a guarantee of unique ownership of an object through move semantics. It is a smart pointer that owns an object and guarantees that only one unique_ptr owns the resource at any given time.

Main points:

• Copying unique_ptr is prohibited (copy constructor and assignment operator are deleted), which prevents having multiple owners.
• Moving a unique_ptr transfers ownership from one pointer to another, leaving the original pointer empty.

Example:

#include <memory>

std::unique_ptr<int> ptr1 = std::make_unique<int>(42);
// std::unique_ptr<int> ptr2 = ptr1; // Error: copying is prohibited
std::unique_ptr<int> ptr2 = std::move(ptr1); // Ownership transferred to ptr2

if (!ptr1) {
    // ptr1 is now empty
}

Thus, std::unique_ptr ensures unique ownership of an object, preventing memory leaks and double deletion errors.