-
Peter Dimov suggested the name 'optional', and was the first to point
out the need for aligned storage.
-
Douglas Gregor developed 'type_with_alignment', and later Eric Friedman
coded 'aligned_storage', which are the core of the optional class implementation.
-
Andrei Alexandrescu and Brian Parker also worked with aligned storage
techniques and their work influenced the current implementation.
-
Gennadiy Rozental made extensive and important comments which shaped
the design.
-
Vesa Karvonen and Douglas Gregor made quite useful comparisons between
optional, variant and any; and made other relevant comments.
-
Douglas Gregor and Peter Dimov commented on comparisons and evaluation
in boolean contexts.
-
Eric Friedman helped understand the issues involved with aligned storage,
move/copy operations and exception safety.
-
Many others have participated with useful comments: Aleksey Gurotov,
Kevlin Henney, David Abrahams, and others I can't recall.
-
William Kempf carefully considered the originally proposed interface
and suggested the new interface which is currently used. He also started
and fueled the discussion about the analogy optional<>/smart pointer
and about relational operators.
-
Peter Dimov, Joel de Guzman, David Abrahams, Tanton Gibbs and Ian Hanson
focused on the relational semantics of optional (originally undefined);
concluding with the fact that the pointer-like interface doesn't make
it a pointer so it shall have deep relational operators.
-
Augustus Saunders also explored the different relational semantics between
optional<> and a pointer and developed the OptionalPointee concept
as an aid against potential conflicts on generic code.
-
Joel de Guzman noticed that optional<> can be seen as an API on
top of variant<T,nil_t>.
-
Dave Gomboc explained the meaning and usage of the Haskell analog to
optional<>: the Maybe type constructor (analogy originally pointed
out by David Sankel).
-
Other comments were posted by Vincent Finn, Anthony Williams, Ed Brey,
Rob Stewart, and others.
-
Joel de Guzman made the case for the support of references and helped
with the proper semantics.
-
Mat Marcus shown the virtues of a value-oriented interface, influencing
the current design, and contributed the idea of "none".
-
Vladimir Batov's design of Boost.Convert library motivated the development
of value accessors for
optional:
functions value, value_or, value_or_eval.
