[boost] Re: boost::optional feature request.

From: Edward Diener (eddielee_at_[hidden])
Date: 2003-03-24 22:27:16

Do you really want the key to an associative container to be an optional
value ? I would be hard-pressed to find a use for that.

Joe Gottman wrote:
>    It would be nice if boost::optional<T> had operator< defined
> whenever operator< was defined for T.   This would allow us to use
> optional<T> as the key of  an associative container.  I suggest the
> following semantics:
>
> bool operator<(optional<T> const &x, optional<T> const &y);
>
> Returns: If y is uninitialized, false.  If  y is initialized and x is
> uninitialized, true.  If x and y are both initialized, (*x < *y).
>
>
>
>    This results in a strict weak ordering with uninitialized
> optional<T> objects being sorted first.