[joosters]

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.