Bug #53846 for Data-Dumper: Necessity of $Data::Dumper::Purity ?

Hi why exists this variable. I can read in the docu: "The default output of self-referential structures can be evaled, but the nested references to $VARn will be undefined, since a recursive structure cannot be constructed using one Perl statement." If it so? If i must use more than one statement in a RValue i used an anonym sub with pretensioned using (eg "sub{}->()"). Inside this sub '*any* referential structures can build and the last statement returned the rebuilded structure. See attached example with "patched" DD output; Thanks