Which combination of overloads is most performant?

I have a function like this:

void init_str(std::string _s)
{
    std::string s{_s};
}

And I want to have an optimization by allowing a const char* overload to avoid creating a temporary std::string.

void init_str(const char* c)
{
    std::string s{c};
}

But I can also use forwarding as well.

template<typename T>
void init_str(T&& t)
{
    std::string s{std::forward<T>(t)};
}

But the preference of overloads by the compiler is:

• const char*


• forwarding


• std::string

So what combination of overloads should I prefer?