Got this to filter out undefined values indirectly from a hash slice:

  my %args = (profile => 'foo');
  my %ta = %args{'profile', 'user', 'password'};
  %ta = map { $_ => $args{$_} } grep { $args{$_ } } keys %ta;
[download]

It works well enough. But in trying to make it a little more concise:

  my %args = (profile => 'foo');
  %ta = map { $_ => $args{$_} } grep { $args{$_ } } keys %args{'profil
+e', 'user', 'password'};
[download]

you get an error: Experimental keys on scalar is now forbidden. Is there a good, more perlish way of pulling this off?