SPL Types
PHP Manual

Introduction

This extension aims at helping people making PHP a stronger typed language and can be a good alternative to scalar type hinting. It provides different typehandling classes as such as integer , float , bool , enum and string

Warning

This extension is EXPERIMENTAL. The behaviour of this extension including the names of its functions and any other documentation surrounding this extension may change without notice in a future release of PHP. This extension should be used at your own risk.


SPL Types
PHP Manual