I really don't understand your example. I substituted warns with prints:

use strict;
use warnings;

my $re =qr{a};
my $re2 =qr{a};
print $re == $re2,"\n";
print $re2 == $re2,"\n";
print 0+$re,"\n";
print 0+$re2,"\n";

[download]

and this is the result:

sini@ordinalfabetix:~$ ./x.pl

1
135589228
135591376
sini@ordinalfabetix:~$

[download]

The last two lines are NOT equal, because are references to two different scalars. And, as a consequence, $re != $re2 (and $re == $re, but it was expected).

So numerical comparison doesn't tell you if two regex are equal, but only if they are the same (reference).

Rule One: "Do not act incautiously when confronting a little bald wrinkly smiling man."

In reply to Re^2: What is the best way to compare variables so that different types are non-equal? by psini
in thread What is the best way to compare variables so that different types are non-equal? by ELISHEVA

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.