Using the postfix syntax, you can chain the operations to first dereference the globref, then the scalarref:

$ alias perle
alias perle='perl -Mstrict -Mwarnings -Mautodie=:all -E'
$ perle 'our $a = 25; my $ra = \*a; say $ra->*{SCALAR}->$*'
25
[download]

Perl has a number of special variables^[perlvar]: $a is one of them (used mainly when sorting); *a is its typeglob.

$ perle '1 for sort { say +(\*a)->*{PACKAGE}; say +(\*a)->*{SCALAR}->$
+*; say $a } 1 .. 3'
main
1
1
main
2
2
[download]

There's also a $b. Everything that applies to $a; also applies to $b.