Add function unlink_if_exists

src/MD_STD.php

@@ -94,6 +94,25 @@ final class MD_STD {
 
     }
 
+    /**
+     * Wrapper around unlink, that explicitly deletes files when existent, but
+     * accepts if they don't. An error is thrown if the files could not be
+     * deleted for other reasons.
+     *
+     * @see https://www.php.net/manual/en/function.unlink.php
+     *
+     * @param non-empty-string $filename File path.
+     *
+     * @return void
+     */
+    public static function unlink_if_exists(string $filename):void {
+
+        if (!\file_exists($filename)) return;
+
+        self::unlink($filename);
+
+    }
+
     /**
      * Gets contents of a folder.
      *