php8-attr-atat.php

<?php
namespace Acme;

use Attribute;

@@Attribute
final class Attr1 {}

@@Attr1
final class Foo {}

$reflectionClass = new \ReflectionClass(Foo::class);
$attributes = $reflectionClass->getAttributes();

var_dump($attributes[0]->newInstance());

php8-attr-rust.php

<?php
namespace Acme;

use Attribute;

#[Attribute]
final class Attr1 {}

#[Attr1]
final class Foo {}

$reflectionClass = new \ReflectionClass(Foo::class);
$attributes = $reflectionClass->getAttributes();

var_dump($attributes[0]->newInstance());