#include <cassert>
#include <typeinfo>

struct Base {
    virtual int score() const { return 1; }
    virtual ~Base() = default;
};
struct Derived : Base {
    int score() const override { return 9; }
};
struct StaticScore {
    int score() const { return 4; }
};
template<class T>
int evaluate(const T& object) { return object.score(); }

bool is_derived(const Base& object) {
    return dynamic_cast<const Derived*>(&object) != nullptr;
}

int main() {
    StaticScore fixed;
    assert(evaluate(fixed) == 4);
    Derived derived;
    Base& reference = derived;
    Base sliced = derived;
    assert(evaluate(reference) == 9);
    assert(sliced.score() == 1);
    assert(dynamic_cast<Derived*>(&reference) == &derived);
    assert(is_derived(reference));
    assert(!is_derived(sliced));
    assert(typeid(reference) == typeid(Derived));
    bool failed = false;
    try {
        (void)dynamic_cast<Derived&>(sliced);
    } catch (const std::bad_cast&) {
        failed = true;
    }
    assert(failed);
}