C++リロードによるクラスメンバーポインタのような機能

コードは次のとおりです.

//: PointerToMemberOperator.cpp
#include <iostream>
using namespace std;

class Dog
{
public:
	int run(int i) const 
	{ 
		cout << "run
";  
		return i; 
	}
	int eat(int i) const 
	{ 
		cout << "eat
";  
		return i; 
	}
	int sleep(int i) const 
	{ 
		cout << "ZZZ
"; 
		return i; 
	}
	typedef int (Dog::*PMF)(int) const;
	// operator->* must return an object 
	// that has an operator():
	class FunctionObject
	{
		Dog* ptr;
		PMF pmem;
	public:
		// Save the object pointer and member pointer
		FunctionObject(Dog* wp, PMF pmf) 
			: ptr(wp), pmem(pmf) 
		{ 
			cout << "FunctionObject constructor
";
		}
		// Make the call using the object pointer
		// and member pointer
		int operator()(int i) const
		{
			cout << "FunctionObject::operator()
";
			return (ptr->*pmem)(i); // Make the call
		}
	};
	FunctionObject operator->*(PMF pmf) 
	{ 
		cout << "operator->*" << endl;
		return FunctionObject(this, pmf);
	}
};

int main() {
	Dog w;
	Dog::PMF pmf = &Dog::run;
	cout << (w->*pmf)(1) << endl;
	pmf = &Dog::sleep;
	cout << (w->*pmf)(2) << endl;
	pmf = &Dog::eat;
	cout << (w->*pmf)(3) << endl;
}