Seems a subset of it. Practicality aside, Perl can autovivify not only hashes but also arrays: my %x; $x{foo}[1]{bar} = 42; # %x is ( foo => [ undef, { ba

Seems a subset of it. Practicality aside, Perl can autovivify not only hashes but also arrays: my %x; $x{foo}[1]{bar} = 42; # %x is ( foo => [ undef, { bar => 42 } ] )