How can I check whether a member function has const overload?

Question

Lets say I have

struct foo {
    void ham() {}
    void ham() const {}
};

struct bar {
    void ham() {}
};

Assuming I have a templated fu

Answer 1

Detector (like is_detected):

template 
using void_t = void;

template  class D, typename = void>
struct detect : std::false_type {};

template  class D>
struct detect>> : std::true_type {};

Sample member verifier:

template 
using const_ham = decltype(std::declval().ham());

Test:

static_assert(detect::value, "!");
static_assert(!detect::value, "!");

DEMO