use strict;
use warnings;
use Benchmark;

our @strings = qw(exception:tex exception:mex asdf tex:exception:mex);

Benchmark::cmpthese( -5, {
    'one'   => q[ my @filtered = grep { /exception:(?!tex)/} @unfiltered; ],
    'two'   => q[ my @filtered = grep { /exception/ && !/tex/ } @unfiltered; ],
    'three' => q[ my @filtered = grep { /exception:/g && !/\Gtex/ } @unfiltered; ],
});