Koha/MoreUtils.pm

   1 package Koha::MoreUtils;
   2
   3 use Modern::Perl;
   4
   5 # From  List::MoreUtils v4.0
   6 sub singleton (@)
   7 {
   8     my %seen = ();
   9     my $k;
  10     my $seen_undef;
  11     grep { 1 == ( defined $_ ? $seen{ $k = $_ } : $seen_undef ) }
  12       grep { defined $_ ? not $seen{ $k = $_ }++ : not $seen_undef++ } @_;
  13 }
  14
  15 1;