#include <iostream>
#include <string_view>

struct Named { virtual std::string_view name() const = 0; virtual ~Named() = default; };
struct Sized { virtual int units() const = 0; virtual ~Sized() = default; };
class Parcel final : public Named, public Sized {
public:
    std::string_view name() const override { return "Crate"; }
    int units() const override { return 3; }
};

int main() {
    Parcel parcel;
    const Named& named = parcel;
    const Sized& sized = parcel;
    std::cout << named.name() << ": " << sized.units() << " units\n";
}