Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/lib/Drupal/Component/Uuid/Uuid.php

@@ -0,0 +1,36 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Component\Uuid\Uuid.
+ */
+
+namespace Drupal\Component\Uuid;
+
+/**
+ * UUID Helper methods.
+ */
+class Uuid {
+
+  /**
+   * The pattern used to validate a UUID string.
+   */
+  const VALID_PATTERN = '[0-9a-f]{8}-([0-9a-f]{4}-){3}[0-9a-f]{12}';
+
+  /**
+   * Checks that a string appears to be in the format of a UUID.
+   *
+   * Implementations should not implement validation, since UUIDs should be in
+   * a consistent format across all implementations.
+   *
+   * @param string $uuid
+   *   The string to test.
+   *
+   * @return bool
+   *   TRUE if the string is well formed, FALSE otherwise.
+   */
+  public static function isValid($uuid) {
+    return (bool) preg_match('/^' . self::VALID_PATTERN . '$/', $uuid);
+  }
+
+}