text: import apply from './_apply.js';
  import createCtor from './_createCtor.js';
  import root from './_root.js';
  
  /** Used to compose bitmasks for function metadata. */
  var BIND_FLAG = 1;
  
  /**
   * Creates a function that wraps `func` to invoke it with the `this` binding
   * of `thisArg` and `partials` prepended to the arguments it receives.
   *
   * @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`.
   * @param {Array} partials The arguments to prepend to those provided to
   *  the new function.
   * @returns {Function} Returns the new wrapped function.
   */
  function createPartial(func, bitmask, thisArg, partials) {
    var isBind = bitmask & BIND_FLAG,
        Ctor = createCtor(func);
  
    function wrapper() {
      var argsIndex = -1,
          argsLength = arguments.length,
          leftIndex = -1,
          leftLength = partials.length,
          args = Array(leftLength + argsLength),
          fn = (this && this !== root && this instanceof wrapper) ? Ctor : func;
  
      while (++leftIndex < leftLength) {
        args[leftIndex] = partials[leftIndex];
      }
      while (argsLength--) {
        args[leftIndex++] = arguments[++argsIndex];
      }
      return apply(fn, isBind ? thisArg : this, args);
    }
    return wrapper;
  }
  
  export default createPartial;
  