FWIW, you can 'lock down' a hash so that reads or writes of non-existing keys will cause a fatal error. Not only does this stop autovivification on 'writes' to

FWIW, you can 'lock down' a hash so that reads or writes of non-existing keys will cause a fatal error. Not only does this stop autovivification on 'writes' to a hash, but it will also help catch typos in your code just reading from the hash: e.g. if you accidentally wrote $foo = $bar{Autovivication} instead of $foo = $bar{Autovivification} in your program, it will abort instead of returning an undefined value :) See Hash::Util for details.