lodash/internal/cachePush.js

define(['./isKeyable'], function(isKeyable) {

  /** Used to stand-in for `undefined` hash values. */
  var HASH_UNDEFINED = '__lodash_hash_undefined__';

  /**
   * Adds `value` to the set cache.
   *
   * @private
   * @name push
   * @memberOf SetCache
   * @param {*} value The value to cache.
   */
  function cachePush(value) {
    var map = this.__data__;
    if (isKeyable(value)) {
      var data = map.__data__,
          hash = typeof value == 'string' ? data.string : data.hash;

      hash[value] = HASH_UNDEFINED;
    }
    else {
      map.set(value, HASH_UNDEFINED);
    }
  }

  return cachePush;
});