std::shared_ptr and std::unique_ptr that assert presence of member pointer on dereferencing

asserting_ptr.hpp

#pragma once

#include <memory>
#include <cassert>

namespace {

template <template <typename...> class H, typename ...A>
class asserting_ptr : public H<A...> {
public:
    template <typename... Args>
    inline asserting_ptr(Args &&... args)
        : H<A...>(::std::forward<Args>(args)...) {}

    inline auto operator->() const -> decltype(H<A...>::operator->()) {
        assert(*this);
        return H<A...>::operator->();
    }
    inline auto operator*() const -> decltype(H<A...>::operator*()) {
        assert(*this);
        return H<A...>::operator*();
    }
};

}

namespace util {

template <typename... B> using ptr = asserting_ptr<::std::shared_ptr, B...>;
template <typename... B> using unique_ptr = asserting_ptr<::std::unique_ptr, B...>;

}