my ($rank) = grep {$sorted_array[$_] eq $my_target} 0..$#sorted_array;
####
sub index_of {
my $thing = shift;
my @indexes = grep $_[$_] eq $thing, 0..$#_;
wantarray ? @indexes : $indexes[0];
}
####
my $rank = index_of($my_target, @sorted_array);
####
my %sorted_index;
$sorted_index{$sorted_array[$_]} = $_ foreach 0..$#sorted_array;
####
my %sorted_index = map {($_, $sorted_array[$_])} 0..$#sorted_array;
####
my @doubled = map {($_, $_)} 1..50_000;
####
my %sorted_index;
@sorted_index{@sorted_array} = 0..$#sorted_array;