[VarDumper] deprecate MongoCaster

src/Symfony/Component/VarDumper/CHANGELOG.md

@@ -5,6 +5,7 @@ CHANGELOG
 -----
 
  * added `AbstractCloner::setMinDepth()` function to ensure minimum tree depth
+ * deprecated `MongoCaster`
 
 2.7.0
 -----

src/Symfony/Component/VarDumper/Caster/MongoCaster.php

@@ -13,10 +13,14 @@ namespace Symfony\Component\VarDumper\Caster;
 
 use Symfony\Component\VarDumper\Cloner\Stub;
 
+@trigger_error('The '.__NAMESPACE__.'\MongoCaster class is deprecated since version 3.4 and will be removed in 4.0.', E_USER_DEPRECATED);
+
 /**
  * Casts classes from the MongoDb extension to array representation.
  *
  * @author Nicolas Grekas <p@tchwork.com>
+ *
+ * @deprecated since version 3.4, to be removed in 4.0.
  */
 class MongoCaster
 {