It is possible (in XS) to put anything in the specific slots:

$ perl -MData::Peek -wC3 \
       -E'my $tv = Data::Peek::triplevar ("\N{GREEK SMALL LETTER PI}", 3, 3.1415);' \
       -e'say for map { $_ // "<undef>" } DDual ($tv)'
π
3
3.1415
<undef>
0

Data::Peek's DDual will return all of those: my ($pv, $iv, $nv, $rv, $hm) = DDual ($var [, $getmagic])