Object.getPrototypeOf(o);

interface ObjectConstructor {
  getPrototypeOf(o: any): any;
}

const proto = {};

const foo = Object.create(proto);
Object.getPrototypeOf(foo) === proto;
// true

const reg = /a/;
Object.getPrototypeOf(reg) === Regexp.prototype;
// true

const foo = new Object();

Object.getPropertyOf(Object);
// f () { [native code] }
Object.getPropertyOf(Function);
// f () { [native code] }

Object.getPropertyOf(Object) === Function.prototype;
// true

const bar = new Object();
Object.prototype === Object.getPrototypeOf(bar);
// true
Obejct.prototype === Object.getPrototypeOf({});
// true