Re: [boost] [outcome] Ternary logic -- need an example

Subject: Re: [boost] [outcome] Ternary logic -- need an example
From: Gavin Lambert (gavinl_at_[hidden])
Date: 2017-05-15 22:56:39

On 16/05/2017 09:42, Niall Douglas via Boost wrote:
> I can already tell that some people will want me to make the assignment
> of the default actions customisable by policy class such that empty is
> not treated so seriously. The good news is that that is very easy to do
> for any end user (simply write a new policy class and go), but I have
> chosen to not document it in the docs. If reviewers feel that
> documenting how to make arbitrary custom editions of basic_monad (soon
> to become basic_outcome) is important and to be encouraged, I can do that.

Presumably people who want an empty state to not be treated as 
error-like could simply use boost::optional<X> for T.

Although technically I suppose that's a different kind of empty state 
than the one you're talking about, but I suspect it's what people are 
really wanting when they say that.

I don't know if it would be worthwhile to try to optimise storage for 
that case.