| 'use strict'; |
| var isObject = require('./_is-object'); |
| var getPrototypeOf = require('./_object-gpo'); |
| var HAS_INSTANCE = require('./_wks')('hasInstance'); |
| var FunctionProto = Function.prototype; |
| // 19.2.3.6 Function.prototype[@@hasInstance](V) |
| if (!(HAS_INSTANCE in FunctionProto)) require('./_object-dp').f(FunctionProto, HAS_INSTANCE, { value: function (O) { |
| if (typeof this != 'function' || !isObject(O)) return false; |
| if (!isObject(this.prototype)) return O instanceof this; |
| // for environment w/o native `@@hasInstance` logic enough `instanceof`, but add this: |
| while (O = getPrototypeOf(O)) if (this.prototype === O) return true; |
| return false; |
| } }); |