Fix various compatibility issues with PHP 8

libs/swiftmailer/classes/Swift/Encoding.php

@@ -0,0 +1,62 @@
+<?php
+
+/*
+ * This file is part of SwiftMailer.
+ * (c) 2004-2009 Chris Corbyn
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/**
+ * Provides quick access to each encoding type.
+ *
+ * @author Chris Corbyn
+ */
+class Swift_Encoding
+{
+    /**
+     * Get the Encoder that provides 7-bit encoding.
+     *
+     * @return Swift_Mime_ContentEncoder
+     */
+    public static function get7BitEncoding()
+    {
+        return self::_lookup('mime.7bitcontentencoder');
+    }
+
+    /**
+     * Get the Encoder that provides 8-bit encoding.
+     *
+     * @return Swift_Mime_ContentEncoder
+     */
+    public static function get8BitEncoding()
+    {
+        return self::_lookup('mime.8bitcontentencoder');
+    }
+
+    /**
+     * Get the Encoder that provides Quoted-Printable (QP) encoding.
+     *
+     * @return Swift_Mime_ContentEncoder
+     */
+    public static function getQpEncoding()
+    {
+        return self::_lookup('mime.qpcontentencoder');
+    }
+
+    /**
+     * Get the Encoder that provides Base64 encoding.
+     *
+     * @return Swift_Mime_ContentEncoder
+     */
+    public static function getBase64Encoding()
+    {
+        return self::_lookup('mime.base64contentencoder');
+    }
+
+    private static function _lookup($key)
+    {
+        return Swift_DependencyContainer::getInstance()->lookup($key);
+    }
+}