Re: Operator Overloading with multiple return types

[eXodiquas via Digitalmars-d-learn]

On Friday, 15 March 2019 at 21:46:50 UTC, Ali Çehreli wrote:
On 03/15/2019 02:43 PM, Sebastiaan Koppe wrote:
On Friday, 15 March 2019 at 21:35:12 UTC, eXodiquas wrote:
Is there any way to achive this behaivour with D2?

Yep. Just make the return type in the function declaration 
`auto`. You are then free to return a different type in each 
static branch.

Or use template constraints:


struct Vector {
  Vector opBinary(string op)(Vector rhs)
    if (op == "+") {
      return Vector();
    }

  double opBinary(string op)(Vector rhs)
    if (op == "/") {
      return 0.5;
    }
}

Ali

Thanks for the quick and simple answers, but I don't get this 
one. If I do it that way the compiler doesn't know which function 
to call, or am I doing something wrong?

Vector2 opBinary(string op)(Vector2 rhs) {
        if (op == "+") {
            return Vector2(this.x + rhs.x, this.y + rhs.y);
        } else if (op == "-") {
            return Vector2(this.x - rhs.x, this.y - rhs.y);
        }
    }

    float opBinary(string op)(Vector2 rhs) {
        if (op == "*") {
            return this.x * rhs.x + this.y * rhs.y;
        }
    }

This gives me the error:
overloads (Vector2 rhs) and (Vector2 rhs) both match argument 
list for opBinary

eXodiquas