MemcachePool Error while not installing `memcached`

[sarahman]

When the memcached (with d suffix) extension is not installed, then the following error is occurred:
Warning: MemcachePool::set(): The lowest two bytes of the flags array is reserved for pecl/memcache internal use in /[project_path]/vendor/previewtechs/simple-cache/src/Memcache.php on line 49.

Please have a look to this error.