Try It Yourself - SyntaxStudy Editor

HTML / CSS / JS

#include <iostream>

// Common base
class Device {
public:
    virtual ~Device() = default;
    void powerOn() const { std::cout << "Device powered on
"; }
};

// Two intermediate classes — use virtual inheritance
class Scanner : virtual public Device {
public:
    void scan() const { std::cout << "Scanning document
"; }
};

class Printer : virtual public Device {
public:
    void print() const { std::cout << "Printing document
"; }
};

// Diamond: inherits Scanner and Printer — only ONE Device subobject
class AllInOne : public Scanner, public Printer {
public:
    void doAll() const {
        powerOn();   // unambiguous — single Device subobject
        scan();
        print();
    }
};

// Interface (abstract class) — preferred over deep hierarchies
class ISerializable {
public:
    virtual std::string serialize() const = 0;
    virtual ~ISerializable() = default;
};

class Document : public ISerializable {
public:
    explicit Document(const std::string& text) : text_(text) {}
    std::string serialize() const override { return text_; }
private:
    std::string text_;
};

int main() {
    AllInOne aio;
    aio.doAll();

ISerializable* doc = new Document("Hello, world");
    std::cout << doc->serialize() << "
";
    delete doc;

return 0;
}