Ideas from C++ SW Design (Klaus Iglberger) and cpp cons I want to write about it - but not sure i can explain as well as Klaus’ book/cpp cons yet Idea still budding…

Ideas from book

• Small Buffer Optimization (SBO): Store small objects inline to avoid heap allocation
• Move semantics: Implement move constructor/assignment for performance
• Value semantics vs Reference semantics: Decide if container owns or references objects
• Virtual function overhead: Each call goes through vtable—consider for hot paths
• Memory allocation: Heap allocation per object unless using SBO
• Exception safety: Ensure strong exception guarantee during copy/assignment
• RTTI trade-off: Type erasure avoids templates but adds runtime indirection

Example from Klaus’ book

class Drawable {
    struct Concept {
        virtual ~Concept() = default;
        virtual void draw() const = 0;
        virtual Concept* clone() const = 0;
    };

    template<typename T>
    struct Model : Concept {
        T obj;
        Model(T o) : obj(std::move(o)) {}
        void draw() const override { obj.draw(); }
        Concept* clone() const override { return new Model(*this); }
    };

    Concept* ptr;

public:
    template<typename T>
    Drawable(T obj) : ptr(new Model<T>(std::move(obj))) {}

    ~Drawable() { delete ptr; }
    Drawable(const Drawable& d) : ptr(d.ptr->clone()) {}
    Drawable& operator=(Drawable d) { std::swap(ptr, d.ptr); return *this; }

    void draw() const { ptr->draw(); }
};

// Usage
struct Circle { void draw() const { /* ... */ } };
struct Square { void draw() const { /* ... */ } };

std::vector<Drawable> shapes;
shapes.push_back(Circle{});
shapes.push_back(Square{});
for (auto& s : shapes) s.draw();