As of at least perl 5.6.0 you can use qr to precompile regexps... so something like... 
$re = qr/$regex/;

$_ =~ $re;

[download]
granted that is not what you asked... but it's much easier and more straightforward if you didn't already know about it.

Update actually since 5.005 it seems

Update2 I tried this... 

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) }
});

[download]
...and got this... 
Benchmark: timing 100000 iterations of a, b, c...
         a:  7 wallclock secs ( 5.92 usr +  0.00 sys =  5.92 CPU) @ 16
+891.89/s (
n=100000)
         b:  5 wallclock secs ( 4.57 usr +  0.00 sys =  4.57 CPU) @ 21
+881.84/s (
n=100000)
         c:  0 wallclock secs ( 0.62 usr +  0.00 sys =  0.62 CPU) @ 16
+1290.32/s
(n=100000)

[download]
putting the compiled re to be much faster... maybe I did something wrong...

                - Ant

In reply to Re: coderef assignment with and without eval by suaveant
in thread coderef assignment with and without eval by sacked

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