operator overloading

[Hexalon]

i am trying to overload this function, but the compiler disagrees.

heres the function.

bool employee::operator == (const employee &p)
{
return *this == p;
}

heres my use of the class and and the overloaded function.

int main(void)
{
employee emp1;
employee emp2;

if(emp1 == emp2)
std::cout << "\n\t\nobjects equal\n\n";

return 0;
}

heres the error the compiler gives.

error C2678: binary '==' : no operator found which takes a left-hand operand of type 'const employee' (or there is no acceptable conversion)

any suggestions.

[Hexalon]

**** smiles!

[galathaea]

You have a circular definition. You define logical equality testing in terms of the same logical equality testing. Instead, do a memberwise test of those things in your class you use to define equality.

[Paul McKenzie]

Originally posted by Hexalon
i am trying to overload this function, but the compiler disagrees.

heres the function.

bool employee::operator == (const employee &p)
{
return *this == p;
}
As galathaea pointed out, you have defined an operator ==, but then you tell it to use the operator == that you are trying to define. Something like this is what you're looking for:

bool employee::operator == (const employee &p)
{
if ( this == &p ) return true;

return (employee.name == p.name &&
employee.address == p.address);

// Or whatever fields you use to compare for equal employees
}

The first == compares pointers. This is a check to see if the instances are the same, not a check to see whether two distinct objects are equal. This is done because there is no need to check if the same instances are equal -- they're always equal.

employee a;
if ( a == a ) // this is covered by the first if() statement

The check for two distinct employee objects being equal is done in the return statement.

employee a;
employee b;
if ( b == a ) // the return statement will be used here.

Regards,

Paul McKenzie