Using C ++ overload to implement functions similar to "class member pointer"

 

The Code is as follows:

 

//: PointerToMemberOperator. cpp

# Include <iostream>

Using namespace std;

 

Class Dog

{

Public:

Int run (int I) const

{

Cout <"run \ n ";

Return I;

}

Int eat (int I) const

{

Cout <"eat \ n ";

Return I;

}

Int sleep (int I) const

{

Cout <"ZZZ \ n ";

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 \ n ";

}

// Make the call using the object pointer

// And member pointer

Int operator () (int I) const

{

Cout <"FunctionObject: operator () \ n ";

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;

}

 

 

From yucan1001