Update to drupal 8.0.0-rc1. For more information, see https://www.drupal.org/node/2582663

vendor/symfony/validator/Constraints/AllValidator.php

@@ -0,0 +1,58 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Validator\Constraints;
+
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\ConstraintValidator;
+use Symfony\Component\Validator\Context\ExecutionContextInterface;
+use Symfony\Component\Validator\Exception\UnexpectedTypeException;
+
+/**
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ *
+ * @api
+ */
+class AllValidator extends ConstraintValidator
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function validate($value, Constraint $constraint)
+    {
+        if (!$constraint instanceof All) {
+            throw new UnexpectedTypeException($constraint, __NAMESPACE__.'\All');
+        }
+
+        if (null === $value) {
+            return;
+        }
+
+        if (!is_array($value) && !$value instanceof \Traversable) {
+            throw new UnexpectedTypeException($value, 'array or Traversable');
+        }
+
+        $context = $this->context;
+
+        if ($context instanceof ExecutionContextInterface) {
+            $validator = $context->getValidator()->inContext($context);
+
+            foreach ($value as $key => $element) {
+                $validator->atPath('['.$key.']')->validate($element, $constraint->constraints);
+            }
+        } else {
+            // 2.4 API
+            foreach ($value as $key => $element) {
+                $context->validateValue($element, $constraint->constraints, '['.$key.']');
+            }
+        }
+    }
+}