Koha/MoreUtils.pm

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