Thread: Need help with overloaded * operator

I'm writing a vector class that will add subtract multiply vectors etc, but I'm having trouble with the * operator. I need to multiply a vector (a complex datatype defined by the class) by an integer, basically scalar multiplication, but I get this error when I compile: error: no match for 'operator*' in '2 * estvec' where 2 is just the integer I used for testing. I tried two ways of doing it but neither of them work. Here is the code:

The public/private declarations of the class (not complete):

Code:

class vector
	{
	private:
		double magnitude;
		double direction;

	public:
		vector();						    //Default consructor
		vector(const vector &old);		          //Copy Constructor

										//Overloaded operators
                //for first method 
		friend vector operator *(const vector &left, const vector &right);
                //for second method.  Note: I only kept one or the other 
		vector operator*(const vector &num);
                                                          
	
	};

Here's the first method:

Code:

	vector operator *(const vector &left, const vector &right)
		{
		vector product;
		product.magnitude = left.magnitude * right.magnitude;
		if (left.magnitude < 0.0)
			{
			product.direction = right.direction + 180.0; 
			}
                //this is based on a 360 degree system
		return product;
		}

Here's the second method:

Code:

	vector vector::operator*(const vector &num)
		{
		 vector result;
		 result.magnitude = magnitude * num.magnitude;
		 result.direction = num.direction;
		 return result;
		}

I simply used this to test the code:

Code:

		vector prod;
		prod = 2 * estvec;        //estvec is just another vector I declared earlier
                cout << prod;               //I have a working overloaded <<  operator