Version 1
[yaffs-website] / node_modules / core-js / library / modules / es6.function.has-instance.js
1 'use strict';
2 var isObject       = require('./_is-object')
3   , getPrototypeOf = require('./_object-gpo')
4   , HAS_INSTANCE   = require('./_wks')('hasInstance')
5   , FunctionProto  = Function.prototype;
6 // 19.2.3.6 Function.prototype[@@hasInstance](V)
7 if(!(HAS_INSTANCE in FunctionProto))require('./_object-dp').f(FunctionProto, HAS_INSTANCE, {value: function(O){
8   if(typeof this != 'function' || !isObject(O))return false;
9   if(!isObject(this.prototype))return O instanceof this;
10   // for environment w/o native `@@hasInstance` logic enough `instanceof`, but add this:
11   while(O = getPrototypeOf(O))if(this.prototype === O)return true;
12   return false;
13 }});