Operator Overload problem. Please help

[l46kok]

I have the code as following
#define PRINT_PER_MINUTE 10;

class Printer
{
private:
int pages;
public:
Printer(int _pages)
{
pages = _pages;
}
int getPrintTime()
{
return pages * PRINT_PER_MINUTE;
}
};

bool Printer::operator<=(const Printer& pri)
{
return getPrintTime() <= pri.getPrintTime();
}

and I am getting an error message which states that "<= is not a member of Printer".

What should I do to fix this problem? Please help.

[jfaust]

#define PRINT_PER_MINUTE 10

class Printer
{
private:
int pages;
public:
Printer(int _pages)
{
pages = _pages;
}

int getPrintTime() const
{
return pages * PRINT_PER_MINUTE;
}
};

bool operator<=(const Printer& lhs, const Printer& rhs)
{
return lhs.getPrintTime() <= rhs.getPrintTime();
}


You either need to declare the operator as part of the class or create it as a function. This code declares it as a function. I also fixed some other issues.

Jeff

[l46kok]

Thanks for the reply.

I've tried adding your code, but I still get an error stating

Printer::getPrintTime' : cannot convert 'this' pointer from 'const Printer' to 'Printer &'

What should I do to fix that problem?

[jfaust]

My code compiles. I tried it. Try again.

Jeff

[l46kok]

Oh it worked for me too. Just forgot to put const on my return function. Thanks

[exterminator]

Operator overloading (http://www.codeguru.com/forum/showpost.php?p=1477025&postcount=6)

[NMTop40]

1. Get rid of the #define
2. use explicit constructor and initialiser list:
3. If the operator is overloaded inside a header declare it inline.
4 However you see a wastage because both of the pages variables are being multiplied by a constant so you know a small optimisation to operator<=. However that means accessing the private variable. You therefore declare it first as a friend.


class Printer
{
private:
enum { PRINT_PER_MINUTE = 10 };

int pages;
public:
explicit Printer(int _pages) : pages ( _pages )
{
}

int getPrintTime() const
{
return pages * PRINT_PER_MINUTE;
}
friend bool operator<= ( const Printer & lhs, const Printer & rhs );
};

inline bool operator<=(const Printer& lhs, const Printer& rhs)
{
return lhs.pages <= rhs.pages;
}