abstract class FooBase<Tf> {
	int get x;
	factory FooBase(int x) = Foo<Tf>;
}

abstract class Foo<T> implements FooBase {
	factory Foo(int x) = Bar<String,T>;
}

class Bar<Sb,Tb> implements Foo<Tb> {
	int x;
	Bar(this.x) {
		print('Bar<$Sb,$Tb>');
	}
}

class Builder<X> {
	method() {
		return new FooBase<X>(4);
	}
}

class SimpleCase<A,B> {
	factory SimpleCase() = SimpleCaseImpl<A,B>;
}

class SimpleCaseImpl<Ai,Bi> implements SimpleCase<Ai,Bi> {
	factory SimpleCaseImpl() = SimpleCaseImpl2<Ai,Bi>;
}

class SimpleCaseImpl2<Ai2,Bi2> implements SimpleCaseImpl<Ai2,Bi2> {
}

class Base<M> {

}
class Mixin<M> {

}

class Mix<M> = Base<M> with Mixin<M>;

main() {
	print(new FooBase<double>(4).x);
	new SimpleCase<int,double>();
	new Mix<double>();
}