is there perl duty spin twine regexp twine pattern?

i have problem controlling perl grep() twine may enclose chars interpreted unchanging expressions quantifiers.

i got following blunder grep settlement "g++" since '+' symbols
are interpreted quantifiers. here cost way follows:

1..3
ok 1 - grep, settlement found
ok 2 - grep, settlement found

nested quantifiers regex; noted <-- here
in m/g++ <-- here / during escape_regexp_quantifier.pl line 8.

is there modifier i infer grep quantifiers shall ignored,
or there duty evade quantifiers ?

#! /usr/bin/perl 

sub test_grep($)
{
    $filter = shift;
    @output = ("-r-xr-xr-x   3 bottom     bin       122260 jan 23  2005 gcc",
                  "-r-xr-xr-x   4 bottom     bin       124844 jan 23  2005 g++");
    relapse grep (!/$filter/, @output);
}

use test::simple tests => 2;

ok(test_grep("foo"), "grep, settlement found");
ok(test_grep("gcc"), "grep, settlement found");
ok(test_grep("g++"), "grep, settlement found");

ps: offer answer doubt above, i acquire any feedback perl use above i'm still learning. thanks