Re: [boost] expected/result/etc

Subject: Re: [boost] expected/result/etc
From: Robert Ramey (ramey_at_[hidden])
Date: 2016-01-27 11:32:41

On 1/25/16 10:16 PM, Michael Marcin wrote:
> Some months ago there was a lot of discussion regarding Rust style
> return values for non-exceptional error handling.
>
> Did anything ever come of this?
> Is there a useable library?
>
> Apologies if I missed an announcement (I've been away for a bit).

I confronted and addressed this problem in the Safe Numerics library.

The data type is called "checked_result<R>". Although it was intended to 
be internal to the library, I did document and test it independently. 
One thing that turned out to be necessary in my application was that it 
be constexpr.

I'm not entirely convinced that a general solution is desirable or even 
possible.  It's a simple data type.  But once you start using it you run 
into application specific issues such as should it be convertible, 
constexpr, etc., ... .  On the other hand, if it is worthwhile, to 
standardize/libraryize/ etc it's going to entail a huge amount of bike 
sheding - as we've already had a taste of.

Robert Ramey