Fwiw Perl 6 only autovivifies anything, including intermediary data structure levels, when writing to a data structure. So nothing happens in this case:
my %h;
dd %h
if %h<foo><bar><baz> { say "Never happens" }
dd %h
Nice, I wasn't aware of that feature, but the features I'm still not aware of in Perl 6 could fill a small book, since I still haven't gotten around to using it for much. :/
