| 'use strict'; | 
| var call = require('../internals/function-call'); | 
| var isCallable = require('../internals/is-callable'); | 
| var isObject = require('../internals/is-object'); | 
|   | 
| var $TypeError = TypeError; | 
|   | 
| // `OrdinaryToPrimitive` abstract operation | 
| // https://tc39.es/ecma262/#sec-ordinarytoprimitive | 
| module.exports = function (input, pref) { | 
|   var fn, val; | 
|   if (pref === 'string' && isCallable(fn = input.toString) && !isObject(val = call(fn, input))) return val; | 
|   if (isCallable(fn = input.valueOf) && !isObject(val = call(fn, input))) return val; | 
|   if (pref !== 'string' && isCallable(fn = input.toString) && !isObject(val = call(fn, input))) return val; | 
|   throw new $TypeError("Can't convert object to primitive value"); | 
| }; |