This attribute is the equivalent of the @template-covariant annotation. It can be applied to a class, trait or interface.
The attribute accepts one string that defines the name of the type variable and an optional string that defines its type. The attribute itself does not have a knowledge of which type variables are valid and which are not and this will depend on the implementation for each particular tool.
We aim to accept all the type variables accepted by static analysis tools for the @template-covariant annotation.
If the class has more than one type variable, you can add a list of TemplateCovariant attributes.
<?php
use Exception;
use PhpStaticAnalysis\Attributes\TemplateCovariant;
#[TemplateCovariant('T')]
#[TemplateCovariant('T', of:Exception::class)]
class TemplateCovariantExample
{
}