use strict;
use warnings;
use Data::Dump qw/dd/;


my $get = sub {
    my ($ref ,@path)=@_;
    for my $member (@path){
        return undef unless exists $ref->{$member};
        $ref = $ref->{$member};
    }
    return $ref;
};



my %hash = ( a=> {b=> {c=> 666} });

dd \%hash;



dd $hash{a}->$get(qw/b c/);
dd $hash{a}->$get(qw/x x x/); # no autovivification
#dd $hash{a}{x}{x}{x};        # autovivification
dd \%hash;

##</code><code>##

{ a => { b => { c => 666 } } }
666
undef
{ a => { b => { c => 666 } } }

##</code><code>##

  $name = $user[$idx]  -> {'name'};           # may create a hash
  $name = $user[$idx]  -> $safe -> {'name'};  # leaves @user alone
  $name = $person      -> name;               # chokes on undef
  $name = $person      -> $safe -> name;      # passes undef on