autodie::hints->set_hints_for(
  \&foo,
  scalar => sub { ! $_ },
  list   => sub { ! @_ or @_ == 1 and ! defined },
);

autodie::hints->set_hints_for(
  \&copy,
  any => sub { ! $_ },
);

autodie::hints->set_hints_for(
  'open',
  any => sub { ! defined },
);