no strict 'refs';
$bla = "something";
$blaref = "bla";
$$blaref = "something else";

print $bla;  # prints "something else"

##</code><code>##

my $subname = "packagename::some_sub";
no strict 'refs';

# note that we use a typeglob here
*$subname = sub {
  print "Hello from subroutine $subname";
};

packagename::some_sub();