use 5.010;
use strict;
use utf8::all;

BEGIN {
	package re::SaneDigits;
	no thanks;
	use overload ();
	
	my %_const_handlers  = (qr => \&_qr);
	my %_remove_handlers = map { $_ => undef } %_const_handlers;
	
	sub import    { overload::constant %_const_handlers }
	sub unimport  { overload::remove_constant %_remove_handlers }
	
	sub _qr
	{
		for (@_) {
			s/\\d/[0-9]/g;
			s/\\D/[^0-9]/g;
			return $_;
		}
	}
};

my $str = "foo23 bar5 bar42";

say $str =~ m/bar(\d+)/i ? "GOT $1" : "NO MATCH";
use re::SaneDigits;
say $str =~ m/bar(\d+)/i ? "GOT $1" : "NO MATCH";