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Simple C++ Operator Overload Problem

I'm trying to overload the division operator in C++ for a class assignment.  The +, - and * are all fine, but I get a weird compilation error for division.  I'm using Visual C++ 2010 Express.

Header file:
#ifndef RATIONALNUMBER_H
#define RATIONALNUMBER_H

using namespace std;

class RationalNumber
{
	friend RationalNumber operator+ (RationalNumber);	
	friend RationalNumber operator- (RationalNumber);	
	friend RationalNumber operator/ (RationalNumber);	
	friend RationalNumber operator* (RationalNumber);	

public:
	RationalNumber(int numerator, int denominator);
	System::String^ toString();
	int getNumerator();
	int getDenominator();

	RationalNumber operator+ (const RationalNumber& r) const;
	RationalNumber operator- (const RationalNumber& r) const;
	RationalNumber operator/ (const RationalNumber& r) const;
	RationalNumber operator* (const RationalNumber& r) const;
	
private:
	int _numerator;
	int _denominator;
	int _wholeNumber;
	bool isValidDenominator(const int denominator);
	void simplifyFraction();
	
};

#endif

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Compilation error I get is:
RationalNumber.h(10): error C2805: binary 'operator /' has too few parameters


Note: if I comment out the / overload, all the other 3 compile fine.
0
rsalvati
Asked:
rsalvati
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2 Solutions
 
jkrCommented:
The key is 'binary operator' - you should use
#ifndef RATIONALNUMBER_H
#define RATIONALNUMBER_H

using namespace std;

// foward declaration
RationalNumber operator/ (const RationalNumber& l, const RationalNumer& r);	

class RationalNumber
{
	// 'friend' is only necessary for non-members	
	friend RationalNumber operator/ (const RationalNumber& l, const RationalNumer& r);	
		

public:
	RationalNumber(int numerator, int denominator);
	System::String^ toString();
	int getNumerator();
	int getDenominator();

	RationalNumber operator+ (const RationalNumber& r) const;
	RationalNumber operator- (const RationalNumber& r) const;
	RationalNumber operator/ (const RationalNumber& r) const;
	RationalNumber operator* (const RationalNumber& r) const;
	
private:
	int _numerator;
	int _denominator;
	int _wholeNumber;
	bool isValidDenominator(const int denominator);
	void simplifyFraction();
	
};

#endif

// ...



RationalNumber operator/ (const RationalNumber& l, const RationalNumer& r);
{
  // implement here
}

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0
 
rsalvatiAuthor Commented:
So you can't over load / as member function the same you would * ?
0
 
jkrCommented:
No, since it is binary. See http://msdn.microsoft.com/en-us/library/5tk49fh2%28VS.80%29.aspx ("Operator Overloading") for a list of operators you can overload and their types.
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Infinity08Commented:
>> So you can't over load / as member function the same you would * ?

You can, but those friend declarations aren't for overloading the operators you think.

You overloaded the unary minus, the unary plus, and the dereference operator, NOT the binary minus, binary plus and binary multiplication operators like you intended.
0
 
rsalvatiAuthor Commented:
Thank you!  I understand now, I wasn't overloading multiply, but the the pointer dereference.
0

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