This is an extended package to the imphp/util that is packed with imphp/base. In order to keep the base as small as possible, only the most widely usable classes is packed with it. This package contains more utility classes that is not packed together with imphp/base.
You can view the Full Documentation to lean more about what this offers.
Using .phar library
wget https://github.com/IMPHP/util/releases/download/<version>/imphp-util.pharrequire "imphp-util.phar";
...Clone via git
git clone https://github.com/IMPHP/util.git imphp/util/Composer (Packagist)
composer require imphp/util