const { ref, trigger, track } = VueReactivity;

let r1 = ref(0);

let r2 = (function(val) { 
  const r = { isRef: true };
  Object.defineProperty(r, "value", {
    get() { track(this, "GET", "value"); return val; }, 
    set(v) { val = v; trigger(this, "value", v); }, 
  });
  return r;
})(0);

let r3 = (function (val) {
  const ref = function (v) {
    if (!arguments.length) {
      track(ref, "GET", "value");
      return val;
    } else {
      val = v;
      trigger(ref, "value", v);
    }
  };
  Object.defineProperty(ref, "value", {
    get: ref,
    set: ref,
    reconfigurable: false
  });
  ref.isRef = true;
  return ref;
})(0);


let r4 = new class {
  constructor(v) {
    this.val = v;
  }
  get value() {
    track(this, "GET", "value");
    return this.val;
  }
  set value(v) {   
    this.val = v;
    trigger(this, "value", v);
  }
  get isRef() { return true; }
}(0);

let r5 = Object.create({
  get value() {
    track(this, "GET", "value");
    return this.val;
  },
  set value(v) {   
    this.val = v;
    trigger(this, "value", v);
  },
  get isRef() { return true; }
});
r5.val = 0;