/** Used as references for various `Number` constants. */
  var MAX_SAFE_INTEGER = 9007199254740991;
  
  /** Used to detect unsigned integer values. */
  var reIsUint = /^(?:0|[1-9]\d*)$/;
  
  /**
   * Checks if `value` is a valid array-like index.
   *
   * @private
   * @param {*} value The value to check.
   * @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index.
   * @returns {boolean} Returns `true` if `value` is a valid index, else `false`.
   */
  function isIndex(value, length) {
    length = length == null ? MAX_SAFE_INTEGER : length;
    return !!length &&
      (typeof value == 'number' || reIsUint.test(value)) &&
      (value > -1 && value % 1 == 0 && value < length);
  }
  
  module.exports = isIndex;