$ perl -Mstrict -Mwarnings -E '
my %x;
my %y = (a => 1);
$x{z} = %y;
say $x{z};
'
1/8

##</code><code>##

$ perl -Mstrict -Mwarnings -E '
my %x;
my %y = (a => 1);
$x{z} = \%y;
say $x{z};
say $x{z}{a};
'
HASH(0x7fba8082b168)
1