etl

5ddc11b5 - Add rvalue accessors to expected and optional, and update constructors. (#690)

Add rvalue accessors to expected and optional, and update constructors. (#690) * Add rvalue methods to optional and expected. * Fix constructors in expected.h. * Fix sanity checks. --------- Co-authored-by: John Wellbelove <jwellbelove@users.noreply.github.com>