Template with default value of method pointer argument

Question

Consider this special container class that stores types that contain both key and value inside it, so

template<typename K, typename T, K (T::*method)() const>
class Container
{
//...
};

K is the type of a key, T is a type of value and the method pointer is used to retreive the key from the value.

It works fine but I would like to include a default for the method pointer so that when it was not specified by the caller it would be operator K() const like so:

template<typename K, typename T, K (T::*method)() const = &T::operator K const>

but this does not compile stating there is no member operator const K on A (<- my class I test this with) when I try to instantiate it (and there is such a method). Is it even possible to have default value of a method pointer template argument? If yes, what is the correct syntax?

EDIT: In addition to the solution below there is a "fix" for the cases when T is a pointer that uses new C++11 feature std::remove_pointer<T>::type, so:

template<typename K, typename T, K (std::remove_pointer<T>::type::*method)() const = &std::remove_pointer<T>::type::operator K>

Answer 1

The name of the function is just operator K. Its qualification isn't part of the name. Try:

template <typename K,
          typename T,
          K (T::*method)() const = &T::operator K>
//                                 ^^^^^^^^^^^^^^