(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
  typeof define === 'function' && define.amd ? define(factory) :
  (global.memoizeOne = factory());
}(this, (function () { 'use strict';

  var simpleIsEqual = function simpleIsEqual(a, b) {
    return a === b;
  };

  function index (resultFn, isEqual) {
    if (isEqual === void 0) {
      isEqual = simpleIsEqual;
    }

    var lastThis;
    var lastArgs = [];
    var lastResult;
    var calledOnce = false;

    var isNewArgEqualToLast = function isNewArgEqualToLast(newArg, index) {
      return isEqual(newArg, lastArgs[index]);
    };

    var result = function result() {
      for (var _len = arguments.length, newArgs = new Array(_len), _key = 0; _key < _len; _key++) {
        newArgs[_key] = arguments[_key];
      }

      if (calledOnce && lastThis === this && newArgs.length === lastArgs.length && newArgs.every(isNewArgEqualToLast)) {
        return lastResult;
      }

      lastResult = resultFn.apply(this, newArgs);
      calledOnce = true;
      lastThis = this;
      lastArgs = newArgs;
      return lastResult;
    };

    return result;
  }

  return index;

})));