I believe that this is taking TIMTOWDI a bit too far.

The most common form I have seen is a list of key-value pairs as the argument list. Using a hashref is generally done only in functions that have been retrofitted to accept keyword options where a hashref was previously forbidden in the argument list.

sub my_func {
  my %params = @_;

  print "Message received: " . $params->{message};
  if ($params->{newline}) { print "\n" }
}
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