text: 'use strict';
  var redefineAll = require('./_redefine-all');
  var getWeak = require('./_meta').getWeak;
  var anObject = require('./_an-object');
  var isObject = require('./_is-object');
  var anInstance = require('./_an-instance');
  var forOf = require('./_for-of');
  var createArrayMethod = require('./_array-methods');
  var $has = require('./_has');
  var validate = require('./_validate-collection');
  var arrayFind = createArrayMethod(5);
  var arrayFindIndex = createArrayMethod(6);
  var id = 0;
  
  // fallback for uncaught frozen keys
  var uncaughtFrozenStore = function (that) {
    return that._l || (that._l = new UncaughtFrozenStore());
  };
  var UncaughtFrozenStore = function () {
    this.a = [];
  };
  var findUncaughtFrozen = function (store, key) {
    return arrayFind(store.a, function (it) {
      return it[0] === key;
    });
  };
  UncaughtFrozenStore.prototype = {
    get: function (key) {
      var entry = findUncaughtFrozen(this, key);
      if (entry) return entry[1];
    },
    has: function (key) {
      return !!findUncaughtFrozen(this, key);
    },
    set: function (key, value) {
      var entry = findUncaughtFrozen(this, key);
      if (entry) entry[1] = value;
      else this.a.push([key, value]);
    },
    'delete': function (key) {
      var index = arrayFindIndex(this.a, function (it) {
        return it[0] === key;
      });
      if (~index) this.a.splice(index, 1);
      return !!~index;
    }
  };
  
  module.exports = {
    getConstructor: function (wrapper, NAME, IS_MAP, ADDER) {
      var C = wrapper(function (that, iterable) {
        anInstance(that, C, NAME, '_i');
        that._t = NAME;      // collection type
        that._i = id++;      // collection id
        that._l = undefined; // leak store for uncaught frozen objects
        if (iterable != undefined) forOf(iterable, IS_MAP, that[ADDER], that);
      });
      redefineAll(C.prototype, {
        // 23.3.3.2 WeakMap.prototype.delete(key)
        // 23.4.3.3 WeakSet.prototype.delete(value)
        'delete': function (key) {
          if (!isObject(key)) return false;
          var data = getWeak(key);
          if (data === true) return uncaughtFrozenStore(validate(this, NAME))['delete'](key);
          return data && $has(data, this._i) && delete data[this._i];
        },
        // 23.3.3.4 WeakMap.prototype.has(key)
        // 23.4.3.4 WeakSet.prototype.has(value)
        has: function has(key) {
          if (!isObject(key)) return false;
          var data = getWeak(key);
          if (data === true) return uncaughtFrozenStore(validate(this, NAME)).has(key);
          return data && $has(data, this._i);
        }
      });
      return C;
    },
    def: function (that, key, value) {
      var data = getWeak(anObject(key), true);
      if (data === true) uncaughtFrozenStore(that).set(key, value);
      else data[that._i] = value;
      return that;
    },
    ufstore: uncaughtFrozenStore
  };
  