Bootstrap.php

<?php

use Doctrine\Common\Annotations\AnnotationRegistry;
use Doctrine\ODM\MongoDB\Mapping\Driver\AnnotationDriver;
use Doctrine\Common\Annotations\AnnotationReader;
use Doctrine\ODM\MongoDB\DocumentManager;

/* @var $loader \Composer\Autoload\ClassLoader */
$loader = require __DIR__.'/vendor/autoload.php';

AnnotationRegistry::registerLoader(array($loader, 'loadClass'));

AnnotationDriver::registerAnnotationClasses();

require_once __DIR__ . '/Parent.php';
require_once __DIR__ . '/Son.php';
require_once __DIR__ . '/Daughter.php';

$driver = new AnnotationDriver(new AnnotationReader(), array(__DIR__));

// @todo instantiate $connection
// @todo instantiate $configuration (with provided metadata driver)

$dm = DocumentManager::create($connection, $configuration);

var_dump($dm->getMetadataFactory()->getAllMetadata());

composer.json

{
    "require": {
        "doctrine/mongodb-odm": "1.0.0-BETA9@BETA"
    }
}

Daughter.php

<?php

namespace my\Bundle\Document\Childs;
use my\Bundle\Document\Parent as Parent;
use Doctrine\ODM\MongoDB\Mapping\Annotations as ODM;

/**
 * @ODM\Document
 */
class Daughter extends Parent 
{
   // ...
}

exception.txt

[Symfony\Component\Debug\Exception\ContextErrorException]                        
  Warning: class_parents(): Class my\Bundle\Document\Childs\Parent  
   does not exist and could not be loaded in /var/www/cogitosum/vendor/doctrine/common/lib/Doctrine/Common/Persistence/Mapping/RuntimeReflectionService.php line 40

Parent.php

<?php

namespace my\GCBundle\Document;
use Doctrine\ODM\MongoDB\Mapping\Annotations as ODM;

/**
 * @ODM\Document (collection="Individual")
 * @ODM\InheritanceType("SINGLE_COLLECTION")
 * @ODM\DiscriminatorField(fieldName="discr")
 * @ODM\DiscriminatorMap({
 *  "Son" =      "my\Bundle\Document\Childs\Son",
 *  "Daughter" = "my\Bundle\Document\Childs\Daughter"
 * })

 */
abstract class Parent
{
    // ...
}

run.sh

#/bin/sh

curl -s https://getcomposer.org/installer | php
php composer.phar install
php Bootstrap.php

Son.php

<?php

namespace my\Bundle\Document\Childs;
use my\Bundle\Document\Parent as Parent;
use Doctrine\ODM\MongoDB\Mapping\Annotations as ODM;

/**
 * @ODM\Document
 */
class Son extends Parent 
{
    // ...
}