--- /dev/null
+<?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\HttpKernel\Controller\ArgumentResolver;
+
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpKernel\Controller\ArgumentValueResolverInterface;
+use Symfony\Component\HttpKernel\ControllerMetadata\ArgumentMetadata;
+
+/**
+ * Yields the default value defined in the action signature when no value has been given.
+ *
+ * @author Iltar van der Berg <kjarli@gmail.com>
+ */
+final class DefaultValueResolver implements ArgumentValueResolverInterface
+{
+ /**
+ * {@inheritdoc}
+ */
+ public function supports(Request $request, ArgumentMetadata $argument)
+ {
+ return $argument->hasDefaultValue() || (null !== $argument->getType() && $argument->isNullable() && !$argument->isVariadic());
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function resolve(Request $request, ArgumentMetadata $argument)
+ {
+ yield $argument->hasDefaultValue() ? $argument->getDefaultValue() : null;
+ }
+}