TinyGPS++ function questions

Below is the function pulled directly out of the header file. For my project I need a degrees value. If I want to store the degree value returned from the internal function:

double TinyGPSPlus::courseTo(double lat1, double long1, double lat2, double long2)
{
  // returns course in degrees (North=0, West=270) from position 1 to position 2,
  // both specified as signed decimal-degrees latitude and longitude.
  // Because Earth is no exact sphere, calculated course may be off by a tiny fraction.
  // Courtesy of Maarten Lamers
  double dlon = radians(long2-long1);
  lat1 = radians(lat1);
  lat2 = radians(lat2);
  double a1 = sin(dlon) * cos(lat2);
  double a2 = sin(lat1) * cos(lat2) * cos(dlon);
  a2 = cos(lat1) * sin(lat2) - a2;
  a2 = atan2(a1, a2);
  if (a2 < 0.0)
  {
    a2 += TWO_PI;
  }
  return degrees(a2);
}

Can i store it like this:

double degrees;

degrees = TinyGPSPlus::courseTo(double lat1, double long1, double lat2, double long2)

and then call the “degrees” value later in the code?

Thanks in advance!

Can i store it like this:

Yes.

and then call the "degrees" value later in the code?

No. You can only call functions. You can USE the degrees value (NO quotes) anywhere it is in scope.

Thank you kindly!