When operator+ is defined inside class, left operand of operator is current instance. So, to declare a overload of operator+ you have 2 choices
inside class, with only one parameter which is right operand
outside of class, with two parameters, left and right operands.
Choice 1: outside class
class Vector
{
private:
double i;
double j;
double k;
public:
Vector(double _i, double _j, double _k)
{
i = _i;
j = _j;
k = _k;
}
Vector& operator+=(const Vector& p1)
{
i += p1.i;
j += p1.j;
k += p1.k;
return *this;
}
//Some other functionality...
};
Vector operator+(const Vector& p1, const Vector& p2)
{
Vector temp(p1);
temp += p2;
return temp;
}
Choice 2: inside class
class Vector
{
private:
double i;
double j;
double k;
public:
Vector(double _i, double _j, double _k)
{
i = _i;
j = _j;
k = _k;
}
Vector& operator+=(const Vector& p1)
{
i += p1.i;
j += p1.j;
k += p1.k;
return *this;
}
Vector operator+(consr Vector & p2)
{
Vector temp(*this);
temp += p2;
return temp;
}
};
