1/**
2 * Checks if `value` is suitable for use as unique object key.
3 *
4 * @private
5 * @param {*} value The value to check.
6 * @returns {boolean} Returns `true` if `value` is suitable, else `false`.
7 */
8function isKeyable(value) {
9  var type = typeof value;
10  return (type == 'string' || type == 'number' || type == 'symbol' || type == 'boolean')
11    ? (value !== '__proto__')
12    : (value === null);
13}
14
15module.exports = isKeyable;
16