#include <iostream>

struct Mom
{
    virtual void play_strategy() const
    {
        std::cout << "Watching television" << std::endl;
    }
    virtual ~Mom() { }
};

struct FemaleChild: Mom
{
    virtual void play_strategy() const override
    {
        std::cout << "Playing with dolls" << std::endl;
    }
};

struct MaleChild: Mom
{
    virtual void play_strategy() const override
    {
        std::cout << "Kicking football around" << std::endl;
    }
};
struct UnrelatedWitchMom
{
    void play_strategy() const
    {
        std::cout << "Killing innocent children" << std::endl;
    }
};

template <typename T,
	  typename = typename std::enable_if<std::is_base_of<Mom, T>::value>::type>
void play_type(T *obj)
{
   obj->play_strategy();
}

int main()
{
    Mom my_mom {};
    Mom *you = new FemaleChild{}, *me = new MaleChild{};

    play_type( &my_mom );
    play_type( you );
    play_type( me );

    UnrelatedWitchMom mom_ah {};
    play_type( &mom_ah );

    delete you;
    delete me;

    return 0;
}