gistfile1.txt

class TypeTest {

	public static function main() {
		myFunc({});
		myFunc({ a: "Hello" });
		myFunc({ b: 1 });
		myFunc({ another: "something" });
	}

	private static function myFunc(o:Opts):Void { }

}

// If I use this I get an error when using { another: "something" }
typedef Opts = {
	@:optional var a:String;
	@:optional var b:Int;
};

// If I use this I get '{ }  should be Opts'
class Opts implements Dynamic {
	var a:String;
	var b:Int;
}

// Ideally I want this, but its not allowed ('cannot only extend classes and anonymous')
typedef Opts = {
	> Dynamic,
	@:optional var a:String;
	@:optional var b:Int;
};