use Benchmark;
use strict;
use List::Util qw(first);
my @x = (0..50000);
Benchmark::cmpthese(1000000, {
 'Grep' => 'my $y  = grep {$_ == 45000} @x',
 'Util' => 'my $y = first {$_ == 45000} @x' });

# Ergibt
          Rate  Util Grep
Util  914077/s   -- -63%
Grep 2463054/s 169%   --