use Benchmark;

sub make_grep {
    my $p = $_[0];
    eval "sub { grep /$p/o, @_ }";
}

sub make_grep2 {
    my $p = $_[0];
    sub { grep /$p/o, @_ };
}
$re = '(ob|[tTs])';
$a = make_grep($re);
$b = make_grep2($re);
$pat = qr/$re/;

timethese(100000,
{
    a => sub { $a->(qw(this is a test bob and jobe)) },
    b => sub { $b->(qw(this is a test bob and jobe)) },
    c => sub { grep $pat, qw(this is a test bob and jobe) }
});