Add twig/string-extra extension

extra/string-extra/src/StringExtension.php

@@ -0,0 +1,31 @@
+<?php
+
+/*
+ * This file is part of Twig.
+ *
+ * (c) Fabien Potencier
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Twig\Extra\String;
+
+use Symfony\Component\String\UnicodeString;
+use Twig\Extension\AbstractExtension;
+use Twig\TwigFilter;
+
+final class StringExtension extends AbstractExtension
+{
+    public function getFilters()
+    {
+        return [
+            new TwigFilter('u', [$this, 'createUnicodeString']),
+        ];
+    }
+
+    public function createUnicodeString(string $text): UnicodeString
+    {
+        return new UnicodeString($text);
+    }
+}