1 var isObject = require('./_is-object')
2 , isArray = require('./_is-array')
3 , SPECIES = require('./_wks')('species');
5 module.exports = function(original){
8 C = original.constructor;
9 // cross-realm fallback
10 if(typeof C == 'function' && (C === Array || isArray(C.prototype)))C = undefined;
13 if(C === null)C = undefined;
15 } return C === undefined ? Array : C;