$ perl -MDevel::Peek -e'Dump(undef); Dump(my $x);'
SV = NULL(0x0) at 0x8168784
  REFCNT = 2147483616
  FLAGS = (READONLY)
SV = NULL(0x0) at 0x817bc18
  REFCNT = 1
  FLAGS = (PADMY)

##</code><code>##

alias my @array = my ($x, $y, $z);

##</code><code>##

sub map_scalars_onto_array(\@@) {
   my $array = shift;
   alias $array->[$_] = $_[0] for 0..$#_;
}

map_scalars_onto_array my @local_array, my ($x, $y, $z);

##</code><code>##

$ perl -E'$#a=5; for (1..2) { say exists($a[3])?1:0; \$a[3]; }'
0
1