Edit File: es6.function.has-instance.js
'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; } });
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