std::unique_ptr is a smart pointer provided by the C++ Standard Library. It is designed to provide exclusive ownership of the dynamically allocated memory while automatically managing the object destruction. It ensures that only one std::unique_ptr can own an object, preventing multiple ownership and resource leaks.

To understand how std::unique_ptr can be used in polymorphism, let’s consider an example scenario where we have a base class Shape and two derived classes Circle and Rectangle. Here’s some code to illustrate this:

#include <memory>

class Shape {
public:
    virtual void draw() const = 0;
    virtual ~Shape() = default; // Polymorphic base class destructor
};

class Circle : public Shape {
public:
	void draw() const override {
		// Draw circle implementation
	}
};

class Rectangle : public Shape {
public:
	void draw() const override {
		// Draw rectangle implementation
	}
};

int main() {
    std::unique_ptr<Shape> shape1 = std::make_unique<Circle>();
    std::unique_ptr<Shape> shape2 = std::make_unique<Rectangle>();

    shape1->draw(); // Calls draw() of Circle class
    shape2->draw(); // Calls draw() of Rectangle class

    return 0;
}

In this example, we define the base class Shape with a pure virtual function draw(). The derived classes Circle and Rectangle inherit from Shape and provide their own implementation of the draw() function.

Inside the main() function, we create std::unique_ptr objects with the base class type and assign them to instances of the derived classes. This demonstrates how std::unique_ptr can be used to manage polymorphic objects. The draw() function is invoked on each std::unique_ptr object using the arrow operator (->), which automatically dispatches to the appropriate derived class implementation.

By using std::unique_ptr with polymorphism, we ensure that the memory allocated for each object is automatically released when the pointer goes out of scope. It eliminates the need for manual memory management and helps prevent memory leaks, which is especially important when dealing with polymorphic objects.

In conclusion, std::unique_ptr is a valuable tool when it comes to managing polymorphic objects in C++. It provides automatic memory management and ensures the correct destruction of objects. Leveraging the power of polymorphism with std::unique_ptr leads to cleaner, safer, and more maintainable code. #polymorphism #stduniqueptr