template <class Return, class Type, class Argument>

 class MemFunctionObject : public binary_function <Type*,Argument,Return>

 {

    Return (Type::*pMemFunction)(Argument);

 public:

   explicit MemFunctionObject( Return (Type::*pMF)(Argument) ) : pMemFunction (pMF)

   {

   }

   Return operator() (Type* pObject, A x) const

   {

      return (pObject->*pMemFunction)(x);

   }

 };

 template <class Result, class Type, class Argument>

 class MemFunctionObjectRef: public binary_function <Type,Argument,S>

 {

 private:

   Result (Type::*pMemMethod)(Argument);

 public:

   explicit MemFunctionObjectRef ( Result (Type::*p)(Argument) ) : pMemMethod (p) {}

   Result operator() (Type& refObject, Argument x) const

     {

          return (refObject.*pMemMethod)(x);

     }

 };

 template <class Arg1, class Arg2, class Result>

 struct binary_function {

     typedef Arg1   first_argument_type;

     typedef Arg2   second_argument_type;

     typedef Result result_type;

 };

 template <class Result, class Type, class Argument>

 MemFunctionObject<Result,Type,Argument> MemFunction(Result (Type::*f)(Argument))

 {

    return MemFunctionObject<Result,Type,Argument>(f);

 }

 // mem_fun example

 #include <iostream>

 #include <functional>

 #include <vector>

 #include <algorithm>

 #include <string>

 using namespace std;

 int main () {

   vector <string*> numbers;

   // populate vector of pointers:

   numbers.push_back ( new string ("one") );

   numbers.push_back ( new string ("two") );

   numbers.push_back ( new string ("three") );

   numbers.push_back ( new string ("four") );

   numbers.push_back ( new string ("five") );

   vector <int> lengths ( numbers.size() );

   transform (numbers.begin(), numbers.end(), lengths.begin(),MemFunction(&string::append,_1,"_test!").length());

   for (int i=; i<; i++) {

       cout << *numbers[i] << " has " << lengths[i] << " letters.\n";

   }

   return ;

 }