List::Util::first bug

list_util_bug.pl

use List::Util qw/first/;
use List::MoreUtils qw/first_value/;
use v5.10;
use Test::More;

is( test('grep'), 4, 'Grep for finding first value' );
is( test('list_util'), 4, 'List::Util::first for finding first value' );
is( test('list_more_utils'), 4, 'List::MoreUtils::first_value for finding first value' );


sub test {
    my $mode = shift;
    my @array = (1..10);
    
    given ($mode) {
        when ('list_util') {
            my $first = first { $_ == 4 } @array;
            return $first;
        }
        when ('list_more_utils') {
            my $first = first_value { $_ == 4 } @array;
            return $first;            
        } 
        when ('grep') {
            my ($first) = grep { $_ == 4 } @array;
            return $first
        } 
        default {
            die "wrong test";  
        }
    }
}

done_testing;