Recursively dereference pointer

Question

While trying to answer one question here, I found this question:

How to recursively dereference pointer (C++03)?

Adapted code from the answer is following:

Answer 1

This is possible with the use of a custom can_dereference trait:

template 
struct can_dereference_helper {
    template ())>
    static std::true_type test(U);
    template 
    static std::false_type test(U...);
    using type = decltype(test(std::declval()));
};

template 
struct can_dereference :
  can_dereference_helper::type>::type {};

and some mutually-recursive functions with a bit'o tag dispatching:

template 
auto recursive_dereference(T&& t, std::false_type) ->
  decltype(std::forward(t)) {
    return std::forward(t);
}

template 
auto recursive_dereference(T&& t) ->
  decltype(recursive_dereference(std::forward(t), can_dereference{}));

template 
auto recursive_dereference(T&& t, std::true_type) ->
  decltype(recursive_dereference(*std::forward(t))) {
    return recursive_dereference(*std::forward(t));
}

template 
auto recursive_dereference(T&& t) ->
  decltype(recursive_dereference(std::forward(t), can_dereference{})) {
    return recursive_dereference(std::forward(t), can_dereference{});
}

See it work live at Coliru. This may seem like overkill compared to Kerrek's answer, but I went for a generic approach that will dereference anything that supports operator*. I'll let you decide which tool fits your problem best.