• Satoshi (29/29) Jun 10 2016 Hello,
• Timon Gehr (6/36) Jun 10 2016 It's an arbitrary limitation.

Satoshi <satoshi gshost.eu> writes:

Hello,
why operator overloading is not working as a static methods 
through the UFCS?

I need overload a << operator in this way:

enum PlatformID {
	None,
	Trinix,
	Unix,
	MacOS,
	Windows
}

PlatformID toPlatformID(string platform) {
	switch (platform.toLower()) {
		case "trinix":  return PlatformID.Trinix;
		case "unix":    return PlatformID.Unix;
		case "macos":   return PlatformID.MacOS;
		case "windows": return PlatformID.Windows;
		default:        return PlatformID.None;
	}
}

void opBinary(string op)(ref PlatformID plat, auto ref const 
string str) if (op == "<<") {
	plat = toPlatformID(str);
}


void thisIsTest() {
	PlatformID id;
	id << "x86_64"; // this is not working
	id.opBinary!("<<")("test"); // but this works O.K.

}

Timon Gehr <timon.gehr gmx.ch> writes:

On 10.06.2016 13:02, Satoshi wrote:
 Hello,
 why operator overloading is not working as a static methods through the
 UFCS?
 ...

It's an arbitrary limitation.
https://issues.dlang.org/show_bug.cgi?id=8062

(The specification has been updated in the meantime, it now documents 
the limitation explicitly. https://dlang.org/spec/operatoroverloading.html)

 I need overload a << operator in this way:

 enum PlatformID {
      None,
      Trinix,
      Unix,
      MacOS,
      Windows
 }

 PlatformID toPlatformID(string platform) {
      switch (platform.toLower()) {
          case "trinix":  return PlatformID.Trinix;
          case "unix":    return PlatformID.Unix;
          case "macos":   return PlatformID.MacOS;
          case "windows": return PlatformID.Windows;
          default:        return PlatformID.None;
      }
 }

 void opBinary(string op)(ref PlatformID plat, auto ref const string str)
 if (op == "<<") {
      plat = toPlatformID(str);
 }


 void thisIsTest() {
      PlatformID id;
      id << "x86_64"; // this is not working
      id.opBinary!("<<")("test"); // but this works O.K.

 }

Yuck. This should at the very least be opAssign instead.