|  | var createCtor = require('./_createCtor'), | 
|  | root = require('./_root'); | 
|  |  | 
|  | /** Used to compose bitmasks for function metadata. */ | 
|  | var WRAP_BIND_FLAG = 1; | 
|  |  | 
|  | /** | 
|  | * Creates a function that wraps `func` to invoke it with the optional `this` | 
|  | * binding of `thisArg`. | 
|  | * | 
|  | * @private | 
|  | * @param {Function} func The function to wrap. | 
|  | * @param {number} bitmask The bitmask flags. See `createWrap` for more details. | 
|  | * @param {*} [thisArg] The `this` binding of `func`. | 
|  | * @returns {Function} Returns the new wrapped function. | 
|  | */ | 
|  | function createBind(func, bitmask, thisArg) { | 
|  | var isBind = bitmask & WRAP_BIND_FLAG, | 
|  | Ctor = createCtor(func); | 
|  |  | 
|  | function wrapper() { | 
|  | var fn = (this && this !== root && this instanceof wrapper) ? Ctor : func; | 
|  | return fn.apply(isBind ? thisArg : this, arguments); | 
|  | } | 
|  | return wrapper; | 
|  | } | 
|  |  | 
|  | module.exports = createBind; |