-WARNING: This section describes an experimental feature. Details may
-change without notice in future versions.
-
-Beginning with release 5.005 of Perl you can use an array reference
-in some contexts that would normally require a hash reference. This
-allows you to access array elements using symbolic names, as if they
-were fields in a structure.
-
-For this to work, the array must contain extra information. The first
-element of the array has to be a hash reference that maps field names
-to array indices. Here is an example:
-
- $struct = [{foo => 1, bar => 2}, "FOO", "BAR"];
-
- $struct->{foo}; # same as $struct->[1], i.e. "FOO"
- $struct->{bar}; # same as $struct->[2], i.e. "BAR"
-
- keys %$struct; # will return ("foo", "bar") in some order
- values %$struct; # will return ("FOO", "BAR") in same some order
-
- while (my($k,$v) = each %$struct) {
- print "$k => $v\n";
- }
-
-Perl will raise an exception if you try to delete keys from a pseudo-hash
-or try to access nonexistent fields. For better performance, Perl can also
-do the translation from field names to array indices at compile time for
-typed object references. See L<fields>.
-