The Role and SwitchUserRole classes are deprecated and will be removed in 5.0. Use strings for roles instead.

The RoleHierarchyInterface is deprecated and will be removed in 5.0.

The getReachableRoles() method of the RoleHierarchy class is deprecated and will be removed in 5.0. Use the getReachableRoleNames() method instead.

The getRoles() method of the TokenInterface is deprecated. Tokens must implement the getRoleNames() method instead and return roles as strings.

The ListenerInterface is deprecated, turn your listeners into callables instead.

The Firewall::handleRequest() method is deprecated, use Firewall::callListeners() instead.

The AbstractToken::serialize(), AbstractToken::unserialize(), AuthenticationException::serialize() and AuthenticationException::unserialize() methods are now final, use getState() and setState() instead.

Before:

public function serialize()
{
    return [$this->myLocalVar, parent::serialize()];
}

public function unserialize($serialized)
{
    [$this->myLocalVar, $parentSerialized] = unserialize($serialized);
    parent::unserialize($parentSerialized);
}

After:

protected function getState(): array
{
    return [$this->myLocalVar, parent::getState()];
}

protected function setState(array $data)
{
    [$this->myLocalVar, $parentData] = $data;
    parent::setState($parentData);
}

MarkingStoreInterface::setMarking() will have a third argument in Symfony 5.0.

Before:

class MyMarkingStore implements MarkingStoreInterface
{
    public function setMarking($subject, Marking $marking)
    {
    }
}

After:

class MyMarkingStore implements MarkingStoreInterface
{
    public function setMarking($subject, Marking $marking , array $context = [])
    {
    }
}