Returning multiple values in C/C++

multiple.c

// Basically in C you only get a single return value,
// but there are ways around that.

// The first, and more common method is to return things using references.
// Pass pointers to the output variables, and write the output values to them.
// While it's common, a lot of people think it's a really bad practice (self included).

void ReturnMultiple1(int a, int b, int *outX, int *outY)
{
  // Write to the output variables.
  *outX = a*3 + b;
  *outY = a*4 - b;
}

void FooBar1()
{
  int x, y;
  ReturnMultiple(1, 2, &x, &y);

  print(x, y);
}

// A better way in my opinion is to use a structure type (even if you only use it once).
// This way the compiler can help guarantee that you actually set all the output values,
// and a number of other things. The code is clearer too.
// I think a lot of people don't realize you can do this.
// For a number of reasons, the compiler can usually generate better machine code for this as well.

// You can use a typedef too, but I usually don't.
struct Vector2 {
  int x, y;
}

struct Vector2 ReturnMultiple2(int a, int b)
{
  struct output = {a*3 + b, a*4 - b};
  return output;
}

void FooBar()
{
  struct Vector2 coord = ReturnMultiple2(1, 2);
  print(coord.x, coord.y);
}