move code to repository root

src/Infrastructure/functions.php

@@ -0,0 +1,23 @@
+<?php declare(strict_types=1);
+
+namespace Lubian\AttributeMagic\Infrastructure;
+
+use function array_filter;
+use function array_values;
+
+/**
+ * @template T
+ * @param array<T> $input
+ * @return array<int, T>
+ */
+function arrayFilter(
+    array $input,
+    callable $callable
+): array {
+    return array_values(
+        array_filter(
+            $input,
+            $callable,
+        )
+    );
+}