Miért ír warning-ot az 57 dik sorban? //C++

//main.cpp

# include <iostream>

# include <stdlib.h>

typedef unsigned short ushort;

typedef unsigned int uint;

using std::cout;

using std::cin;

using std::endl;

class Counter

{

public:

Counter(int x); //Konstruktor

Counter(const Counter &); //Másoló konstruktor

~Counter(); //Destruktor

void increment(); //increment

const Counter& operator++ (); //prefix

const Counter operator++ (int); //postfix

void SetVal(int x); //SetVal

int GetVal()const; //GetVal

private:

int *itsVal;

};

//konst,copy konst,destr,

Counter::Counter(int x):

itsVal(new int(x))

{cout <<"Konstruktor \n";}

Counter::Counter(const Counter &rhs)

{

cout <<"Copy konstruktor \n";

itsVal = new int;

*itsVal = rhs.GetVal();

}

Counter::~Counter()

{

cout <<"Destruktor \n";

delete itsVal;

itsVal = NULL;

}

//operator++

const Counter& Counter::operator++ ()

{

++*itsVal;

return *this;

}

const Counter Counter::operator++ (int)

{

*itsVal++; //ez a 57-dik sor.

return *this;

}

//Metódus

void Counter::SetVal(int x)

{*itsVal = x;}

int Counter::GetVal()const

{return *itsVal;}

void Counter::increment()

{++*itsVal;}

//main kezdõdik

int main()

{

Counter i(1);

cout <<"i erteke: "<< i.GetVal() << endl;

++i;

cout <<"i erteke: "<< i.GetVal() << endl;

return EXIT_SUCCESS;

}

//C:\Users\ALWAYS_WINS\Desktop\Code Blocks mentesek\Practice_5\main.cpp|57|warning: value computed is not used [-Wunused-value]|