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Overloading Input Operator

ldelsignore (57)
I cannot get my function overloading the input operator for rational type objects to work. Can anyone help?


lab9.cpp: In function ‘std::istream& operator>>(std::istream&, const rational&)’:
lab9.cpp:186:20: error: invalid initialization of reference of type ‘std::istream& {aka std::basic_istream<char>&}’ from expression of type ‘rational’
return (inputFrac);



lab9.h
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#include <iostream>
using namespace std;




class rational
{

public:

	rational();

	rational(int a, int b);

	int getNumerator() {return numerator;};

	int getDenomnator() {return denominator;};

	rational operator+(const rational &);

	rational operator-(rational);

	rational operator*(rational);

	rational operator/(rational);

	bool operator!=(rational);

	bool operator==(rational);

	bool operator>(rational);

	bool operator<(rational);

	bool operator>=(rational);

	bool operator<=(rational);

	rational operator-();

	friend ostream& operator<<(ostream& outs, const rational& frac);

	friend istream& operator>>(istream& ins, const rational& frac);



private:

	int numerator;
	int denominator;

};




lab9main.cpp
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#include <iostream>
#include "lab9.h"

using namespace std;


int main(){

	string op;

	rational a, b;
	
	cout << "Let's start to test operators defined on rational class." << endl;

	cout << "Enter the operator (+, -, *, /, == .... enter -1 for negation):" << endl;
	
	cin >> op;

	if (op == "-1")
		cout << "Enter the operand." << endl;
		
	else
		cout << "Enter the two operands." << endl;
		cin >> a >> b;	



	return 0;
}







lab9.cpp
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#include <iostream>
#include <assert.h>
#include "lab9.h"
using namespace std;


	rational::rational()
	{
		numerator = 0;
		denominator = 0;
	}

        rational::rational(int a, int b)
	{
		numerator = a;
		denominator = b;
	}

        rational rational::operator+(const rational & frac)
	{
		rational addFrac;

		int temp1 = numerator, temp2 = denominator;
		int temp3 = frac.numerator, temp4 = frac.denominator;

		temp1 *= frac.denominator;
		temp2 *= frac.denominator;

		temp3 *= denominator;
		temp4 *= denominator;
	
		addFrac.numerator = temp1 + temp3;
		assert(temp4 == temp2);
		addFrac.denominator = temp2;

		return(addFrac);
	}

	rational rational::operator-(rational frac)
	{
		rational subFrac;
		
		int temp1 = numerator, temp2 = denominator;
                int temp3 = frac.numerator, temp4 = frac.denominator;

                temp1 *= frac.denominator;
                temp2 *= frac.denominator;

                temp3 *= denominator;
                temp4 *= denominator;

		subFrac.numerator = temp1 - temp3;
		assert(temp4 == temp2);
		subFrac.denominator = temp2;

		return(subFrac);	
	}

	rational rational::operator*(rational frac)
	{
		rational timesFrac;

		timesFrac.numerator = numerator * frac.numerator;
		timesFrac.denominator = denominator * frac.denominator;

		return(timesFrac);
	}

	rational rational::operator/(rational frac)
	{
		rational divFrac;

		divFrac.numerator = numerator * frac.denominator;
		divFrac.denominator = denominator * frac.numerator;

		return(divFrac);
	}


	bool rational::operator!=(rational frac)
	{
		if ((numerator * frac.denominator) == (denominator * frac.numerator))
                        return true;
                else
                        return false;
	}

	bool rational::operator==(rational frac)
	{
		if ((numerator * frac.denominator) == (denominator * frac.numerator))
			return false;
		else
			return true;
	}

	bool rational::operator>(rational frac)
	{

		double(numerator);
		double(denominator);
		double(frac.numerator);
		double(frac.denominator);

		if ((numerator / denominator) > (frac.numerator / frac.denominator))
			return true;
		else
			return false;
	}

	bool rational::operator<(rational frac)
        {

                double(numerator);
                double(denominator);
                double(frac.numerator);
                double(frac.denominator);

                if ((numerator / denominator) < (frac.numerator / frac.denominator))
                	return true;
                else
			return false;
        }

	bool rational::operator>=(rational frac)
        {
                double(numerator);
                double(denominator);
                double(frac.numerator);
                double(frac.denominator);

                if ((numerator / denominator) > (frac.numerator / frac.denominator))
			return true;
                else if ((numerator / denominator) < (frac.numerator / frac.denominator))
                        return false;
		else
			return true;
        }

	bool rational::operator<=(rational frac)
        {
                double(numerator);
                double(denominator);
                double(frac.numerator);
                double(frac.denominator);

                if ((numerator / denominator) < (frac.numerator / frac.denominator))
                        return true;
                else if ((numerator / denominator) > (frac.numerator / frac.denominator))
               		return false;
		 else
			return true;
        }

	rational rational::operator-()
	{
		rational negativeFrac;

		negativeFrac.numerator = -1 * numerator;

		return (negativeFrac);

	}
	

	ostream& operator<<(ostream& outs, const rational& frac)
	{
		outs << frac.numerator << "/"  << frac.denominator << endl;
	}
	
	istream& operator>>(istream& ins, const rational& frac)
	{

		rational inputFrac;

		char slash;	

		ins >> inputFrac.numerator;

		do
			ins >> slash;
		while (slash != '/');
	
		ins >> inputFrac.denominator;

		return (inputFrac);

	}
Smac89 (1727)
Your function should be returning an istream object not a rational object
ldelsignore (57)
I don't really understand streams. Can you please tell me what I should return if I want to use the operator to input an object that represents a fraction as I have thus far done in this program?
Smac89 (1727)
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istream& operator>>(istream& ins, rational& frac)
{	
	ins >> frac.numerator;
	while (ins.get() != '/');
	ins >> frac.denominator;

	return ins; // return the istream object
}
ldelsignore (57)
I've got it, thanks.
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