Why is boolean printed as a number? [duplicate]

This question already has an answer here:

• C++ printing boolean, what is displayed? [closed] 2 answers

I am a bit curious why my code prints a number instead of bool value.

class fb
{
public:
    bool p;

    void
    func()
    {
        memset(&(p), 4, 1);
    }
};

int
main()
{
    fb f;

    f.func();

    std::cout << f.p << std::endl;

    return 0;
}

My code prints number "4" and I am not really sure why this happens. Can you please explain me what is wrong with my code? I was expecting that result will be "true".

Thank you