With a tied array it should be feasable to always access @$ref. ( well quite slow but good enough for a showcase.)

> And you can't magic your way out of it 

These variables are scoped and easy to identify (at least lexicals) you can just replace every @arr with @$are at compile time or in a macro substitution.

>  because sometimes only the stringified ref is kept (as the key of a hash).

I doubt that's documented or guaranteed behavior.

At least with stash variables you are free to change the reference by aliasing.

Just try *a=\@b; and see what \@a returns. :)

update

furthermore this allows changing the underlying reference.

use 5.22.0;
use feature qw/say refaliasing/;
no warnings "experimental::refaliasing";

my @a=(1,2,3);
my @b=(3,2,1);

say \@a;

\@a=\@b;

say \@a;
[download]

I doubt that's documented or guaranteed behavior.

It's present in the Inside Out objects documentation at least. And the perlref doc states

Using a reference as a string produces [...] the numeric address expressed in hex.

Which is used to see if the two references refer to the same location. There's nothing that explictly states that a lexical variable will have a constant address for the duration of its scope though. And I didn't know that this was already broken by the experimental refaliasing, because I would expect that CPAN modules use constructs like process(@a) unless $processed{\@a}; which would break if the address is not constant. At least refaliasing makes it explicit that you are "overwriting the reference", because \@a=\@b; is not valid in "classic perl", so you're either going to guess what it does, or think it's a syntax error. Same goes with your declaration proposition. The declaration syntax wouldn't just be about type security, but rather about new features being a syntax error if used outside their scope.

I didn't mention globs because while they make it easy to have an array always be the thing a references refers to, they can't be used with lexicals alone. Once again though, this was for lack of knowledge that aliasing is possible between lexicals. I now know that your proposition can be implemented (or at least emulated) using existing features.

I still like $array being read-only better though, because it would make it possible to have a reference bound to your array for ease of use, without the side effects, or even misleading perl newcomers into believing that $array = [1..3]; overwrites the values of the array instead of creating a brand new one.

Edit: tr/$/&/ in html escape :)

And do you think this would improve the usability of Perl for beginners? (I do)

Could rather than would. I'm sure a significant portion of them would avoid a syntax that looks like additional effort (because who doesn't know that error messages are more effort than debugging blindly and getting confusing behaviour?) as they already avoid strict which is just one line and not "extra noise".