ClassMeta *   CLASSMETA
FieldMeta *   FIELDMETA
MethodMeta *  METHODMETA

INPUT
CLASSMETA
  $var = MUST_CLASSMETA_FROM_RV($arg);

FIELDMETA
  $var = MUST_FIELDMETA_FROM_RV($arg);

METHODMETA
  $var = MUST_METHODMETA_FROM_RV($arg);