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Subject: Re: [boost] [outcome] Second high level summary of review feedback accepted so far
From: Niall Douglas (s_sourceforge_at_[hidden])
Date: 2017-05-30 17:24:50

On 30/05/2017 17:11, Peter Dimov via Boost wrote:
> Niall Douglas wrote:
>> 1. I have been persuaded to use longer more appropriate naming for
>> result<T> and outcome<T>, so now the typedefed varieties with implicit
>> conversions to their empty-capable form indicated by "=>" are:
>> - static_checked_outcome<T> => static_checked_optional_outcome<T>
>> static_checked_result<T> => static_checked_optional_result<T>
> ...
>> - runtime_checked_outcome<T> => runtime_checked_optional_outcome<T>
>> runtime_checked_result<T> => runtime_checked_optional_result<T>
> ...
>> Nobody is proposing that end users actually type out the full name
>> each and every time they use them, and the documentation will make
>> that clear.
> As I already said, for me this takes away the whole point of the
> library, which is to provide STANDARD result types which people use in
> their public APIs.

This is not and never has been the whole point of the proposed library.

Do you accept that the static checked and runtime checked varieties are
orthogonal user bases? There is a camp of users who strongly prefer no
runtime overhead and static checking. There is also a camp of users who
strongly prefer no UB possible in an uncertainty returning object.

I can see a point to both camps. Neither is obviously wrong. So seeing
as Outcome's **actual** primary goal is to provide a lightweight
universal error handling system which eases integration of arbitrary
third party libraries each with their own preferred choice of error
handling strategy, the choice to provide both options with zero cost
conversion and interoperation is the obvious one to me.

That's the whole point and vision of Outcome. The design of the one true
result type for C++ is exclusively on Vicente and WG21 LEWG to come up
with. Outcome will support whatever they decide.

I appreciate that isn't what you want for Outcome Peter. You want a
standard result type here and now. But that's Vicente's turf, best argue
for that there. Outcome is here to grease the wheels between differences
in design choice, not to declare any one right way. WG21 are better
suited to do that.


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