Using generic std::function objects with member functions in one class

Question

For one class I want to store some function pointers to member functions of the same class in one map storing std::function objects. But I fail rig

Answer 1

If you need to store a member function without the class instance, you can do something like this:

class MyClass
{
public:
    void MemberFunc(int value)
    {
      //do something
    }
};

// Store member function binding
auto callable = std::mem_fn(&MyClass::MemberFunc);

// Call with late supplied 'this'
MyClass myInst;
callable(&myInst, 123);

What would the storage type look like without auto? Something like this:

std::_Mem_fn_wrap callable

You can also pass this function storage to a standard function binding

std::function binding = std::bind(callable, &testA, std::placeholders::_1);
binding(123); // Call

Past and future notes: An older interface std::mem_func existed, but has since been deprecated. A proposal exists, post C++17, to make pointer to member functions callable. This would be most welcome.