Getting data returned into auto to new double

Question

I am working with code that returns 2 doubles into an auto named "coordinate". I am inexperienced with with the auto type and all I am trying to do is get the data into "normal" variables that I could work with as I desire. Here is what I am working with :

auto coordinate = CoordinateToCoordinate(lat, lon, angle, dist);

The return is always something like "29.29324, -101.43932". How do I get each double into a variable I can work with?

It would be perfect to place them into 2 names like the ones below. After reading online and here I have been unable to find anything that (atleast on my skill level) is enough to help me understand how to even start.

double latitude;
double longitude;

Edit : This is most of the code where I am having trouble understanding - most of it is beyond my understanding, though I am trying.

std::pair<double,double> CoordinateToCoordinate (double latitude,
                                                 double longitude,
                                                 double angle,
                                                 double meters)
{
  latitude = degreeToRadian(latitude);
  longitude = degreeToRadian(longitude);
  angle = degreeToRadian(angle);
  meters *= 2 / earthDiameterMeters;

  using namespace std;
  pair<double,double> coordinate;

  coordinate.first = asin((sin(latitude) * cos(meters))
                        + (cos(latitude) * sin(meters) * cos(angle)));
  coordinate.second = longitude + atan2((sin(angle) * sin(meters) * cos(latitude)),
                                        cos(meters) - (sin(latitude) * sin(coordinate.first)));

  coordinate.first = radianToDegree(coordinate.first);
  coordinate.second = radianToDegree(coordinate.second);

  return coordinate;
}

`auto` is just a placholder for the actual type. What does `CoordinateToCoordinate` return? — 463035818_is_not_an_ai, Oct 29 '18 at 12:53
It seems the return is a string, not a pair of double, so not a duplicate from this question. But not clear enough. — Matthieu Brucher, Oct 29 '18 at 12:55
`auto coordinates = CoordinateToCoordinate(...);` `latitude = coordinates.first; longitude = coordinates.second;` Or if you have C++17 or higher: `[latitude, longitude] = CoordinateToCoordinate(...);` — Rinat Veliakhmedov, Oct 29 '18 at 13:04
@RinatVeliakhmedov Between C++11 and C++17 you can `std::tie(longitude, latitude) = CoordinateToCoordinate(...);`. — François Andrieux, Oct 29 '18 at 13:13
I'd be wary of using 6-digit precision from code that assumes the Earth is a sphere. — Toby Speight, Oct 30 '18 at 12:02

Getting data returned into auto to new double

0 Answers0