sidecasting with dynamic_cast in C++

mi_dynamic.cpp

#include <iostream>
#include <memory>
#include <vector>

struct base {
    virtual ~base() = default;
};

struct capability1 {
    virtual void do_capability1() = 0;
};

struct capability2 {
    virtual void do_capability2() = 0;
};

template<class T>
struct capability3 {
    virtual void do_capability3(T x) = 0;
};

struct A : base, capability1 {
    void do_capability1() { std::cout << "A capability1\n"; }
};

struct B : base, capability2 {
    void do_capability2() { std::cout << "B capability2\n"; }
};

struct C : base, capability1, capability2 {
    void do_capability1() { std::cout << "C capability1\n"; }
    void do_capability2() { std::cout << "C capability2\n"; }
};

struct D : base, capability3<int> {
    void do_capability3(int x)
    {
        std::cout << "D capability3 with: " << x << '\n';
    }
};

struct E : base, capability3<int>, capability3<const char*> {
    void do_capability3(int x)
    {
        std::cout << "E capability3 with: " << x << '\n';
    }

    void do_capability3(const char* x)
    {
        std::cout << "E capability3 with: " << x << '\n';
    }
};

int main()
{
    std::vector<std::unique_ptr<base>> objs;
    objs.emplace_back(std::make_unique<A>());
    objs.emplace_back(std::make_unique<B>());
    objs.emplace_back(std::make_unique<C>());
    objs.emplace_back(std::make_unique<D>());
    objs.emplace_back(std::make_unique<E>());

    for (const auto& p : objs) {
        if (auto* c1 = dynamic_cast<capability1*>(p.get())) {
            c1->do_capability1();
        }

        if (auto* c2 = dynamic_cast<capability2*>(p.get())) {
            c2->do_capability2();
        }

        if (auto* c3i = dynamic_cast<capability3<int>*>(p.get())) {
            c3i->do_capability3(45);
        }

        if (auto* c3s = dynamic_cast<capability3<const char*>*>(p.get())) {
            c3s->do_capability3("hello");
        }

        if (auto* c3d = dynamic_cast<capability3<double>*>(p.get())) {
            c3d->do_capability3(47.8);
        }
    }

    return 0;
}