@:overload and @:macro via andy li google groups haxe mailing list

VarArgMacro.hx

// https://groups.google.com/d/msg/haxelang/IAqSXSREyHA/hjq-ZcLAcr4J

@:overload(function(a:Dynamic,b:Dynamic):Void{})
@:overload(function<A,B,C>(a:A, b:B, c:C):C{})
@:macro public static function foo(args:Array<Expr>):Expr {
  return switch (args.length) {
           case 2: args[0];
           case 3: args[2];
           default: throw "wrong args";
       }
}