CODEWITHSUNDEEP
c++pointersreferenceoperator-overloading
M. Meacham
M. Meacham

Reputation: 121

Learning about Overloading Operators. Getting "non-standard syntax; use '&' to create a pointer to a member" error

I am trying to create a simple program that uses an overloaded operator. I believe I have that part correct. But when I try to call my "getDollar" function in my "Money" class, I get "non-standard syntax; use '&' to create a pointer to a member" error. What am I missing?

Thanks for the help. (Code posted below)

Driver.cpp

#include <iostream>
#include "Money.h"

using namespace std;

// Declaring Variables
Money a;
Money b;

int cents;
int dollars;

// Main Function
int main()
{
    cout << "Please enter in a monetary value:\n" << "Dollars: ";
    cin >> dollars;
    cout << "\nCents: ";
    cin >> cents;

    Money a(dollars, cents);

    cout << "Please enter in second monetary value:\n" << "Dollars: ";
    cin >> dollars;
    cout << "\nCents: ";
    cin >> cents;

    Money b(dollars, cents);

    Money& c = a + b;

    cout << "\nThe amount of the two added together are " << c.getDollars << "." << c.getCents << endl;

    c = a - b;

    cout << "\nThe amount of the first value subtracted by the second value is " << c.getDollars << "." << c.getCents << endl;


    system("PAUSE");
    return 0;
}

Money.cpp

#include "Money.h"
#include <iostream>

using namespace std;


Money::Money()
{
    dollars = 0;
    cents = 0;
}


Money::Money(int d, int c)
{
    dollars = d;
    cents = c;
}

int Money::getDollars() const
{
    return dollars;
}

int Money::getCents() const
{
    return cents;
}

Money Money::operator+ (const Money& otherMoney)
{
    // Declare a new "Money" object
    Money newMoney;

    // Add the cents from money object 1 and money object 2
    newMoney.cents = cents + otherMoney.cents;

    // Add the dollars from money object 1 and money object 2
    newMoney.dollars = dollars + otherMoney.dollars;

    // Return the new money object
    return newMoney;
}

Money Money::operator- (const Money& otherMoney)
{
    // Declare a new "Money" object
    Money newMoney;

    // Subtract the cents of money object to FROM money object 1
    newMoney.cents = cents - otherMoney.cents;

    // Subtract the dollars of money object to FROM money object 1
    newMoney.dollars = dollars - otherMoney.dollars;

    // Return the new money object
    return newMoney;
}

Money.h

#pragma once
#include <iostream>

using namespace std;

class Money
{
private:
    int dollars;
    int cents;

public:
    // Default Constructor
    // Purpose: Remove any data
    // Parameter: Void
    // Return: None
    Money();

    // Parameterized Constructor
    // Purpose: Set dollars and cents equal to "d" and "c"
    // Parameter: two ints, "d" and "c"
    // Return: None
    Money(int, int);

    // getDollars Function
    // Purpose: Returns dollars
    // Parameter: None
    // Return: int (dollars)
    int getDollars() const;

    // getCents Function
    // Purpose: Returns cents
    // Parameter: None
    // Return: int (cents)
    int getCents() const;

    // + Operator Overload
    // Purpose: Add the money of two different Money Objects together
    // Parameter: Money Object
    // Return: Money Object
    Money operator+ (const Money&);

    // - Operator Overload
    // Purpose: Subtract the money of one Money object from another
    // Parameter: Money Object
    // Return: Money Object
    Money operator- (const Money&);
};

Upvotes: 0

Views: 532

Answers (3)

flogram_dev
flogram_dev

Reputation: 42858

You can't use a non-const lvalue reference to refer to a temporary.

Money& c

should be

Money c

Upvotes: 0

R Sahu
R Sahu

Reputation: 206667

To call getDollars function on the object, you need to use the function call syntax. Instead of 

cout << "\nThe amount of the two added together are "
     << c.getDollars << "." << c.getCents << endl;

use

cout << "\nThe amount of the two added together are "
     << c.getDollars() << "." << c.getCents() << endl;
     //             ^^                     ^^

The compiler is not very helpful in guiding you to the solution. It's guessing that, maybe, you wanted to get a pointer to the member function and not make the function call. To get the a pointer to the member function, you'll need to use &Money::getDollars.

Upvotes: 0

Shokwav
Shokwav

Reputation: 664

You are forming a pointer-to-member like so:

instance.function

However, the standard way of forming a pointer-to-member is like this:

&(instance.function)

Some compilers will silently accept your way, but most will at least complain about it, since it is technically non-portable.

However, I doubt you're actually trying to form a pointer-to-member. In that case, you just forgot the parenthesis around your functions in the cout statements.

Upvotes: 2

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