Init

.gitignore

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+*.o
+.*.swp

Makefile

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+run: wrappers
+	./wrappers
+
+wrappers: main.c
+	g++ -Wall -o wrappers main.c
+
+clean:
+	rm -f *.o wrappers

main.c

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+#include <iostream>
+
+struct IShape {
+	virtual void draw() const = 0;
+	virtual ~IShape() = default;
+};
+
+class Circle : public IShape {
+public:
+	void draw() const override {
+		std::cout << "Circle::draw()\n";
+	}
+};
+
+
+template<typename T>
+class Wrapper {
+	T* impl;
+
+public:
+	Wrapper(T* obj) : impl(obj) {}
+
+	T* operator->() { return impl; }
+	const T* operator->() const { return impl; }
+
+	operator T*() { return impl; }
+	operator const T*() const { return impl; }
+
+	operator T&() { return *impl; }
+	operator const T&() const { return *impl; }
+};
+
+void render_shape_by_ptr(IShape* shape) {
+	shape->draw();
+}
+
+void render_shape_by_ref(IShape& shape) {
+	shape.draw();
+}
+
+int main() {
+	Circle c;
+	Wrapper<IShape> w(&c);
+
+	w->draw();
+
+	render_shape_by_ptr(w);
+
+	render_shape_by_ref(w);
+}