Static dispatch with C++ templates

static_dispatch_tmpr.cpp

#include <cstdlib>
#include <iostream>

using namespace std;

struct Functor {
	inline int operator () (int i, char c) {
		return i+c;
	}
};

struct SpecFunctor {
	inline char operator () () {
		return 'a';
	}
};

template <int N>
struct Sel {
	enum {
		sel = N
	};
};

namespace OuterName {
	template <typename S> 
	struct Inner {
		typedef Functor method;
	};
	
	template <>
	struct Inner< Sel<1> > {
		typedef SpecFunctor method;
	};

	struct Outer {
		template <typename T>
		inline typename Inner<T>::method operator [] (T) {
			typename Inner<T>::method f;
			return f;
		}
	};
}

#define ID(n) [Sel<n>()]

int main() {
	OuterName::Outer obj;
	//cout << obj ID(0)(2,3) << endl;
	char c = obj ID(1)();
	//cout << obj ID(1)() << endl;
	return EXIT_SUCCESS;
}