use Hash::Util::FieldHash or ties, depending on availability
Under older perls this module provides a drop in compatible api to
Hash::Util::FieldHash using perltie.  When Hash::Util::FieldHash is
available it will use that instead.
This way code requiring field hashes can benefit from fast, robust field
hashes on Perl 5.10 and newer, but still run on older perls that don't
ship with that module.

Maintainer: The OpenBSD ports mailing-list <ports@openbsd.org>

WWW: http://search.cpan.org/dist/Hash-Util-FieldHash-Compat/
