Another way to go might have been to use an attribute for you iterator variable, which ties it into a ProgBar tie-scalar class at declaration time.

Unfortunately using attributes in for loops doesn't seem to be implemented.

  DB<58> for my $i :progbar (1..10) { print $i }

syntax error at (eval 69)[C:/Perl_524/lib/perl5db.pl:737] line 2, near
+ "$i :"
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and of course this wouldn't work with implicit $_.