Re: [boost] [outcome] To variant, or not to variant?

Subject: Re: [boost] [outcome] To variant, or not to variant?
From: Gavin Lambert (gavinl_at_[hidden])
Date: 2017-06-01 08:25:06

On 1/06/2017 19:29, Andrzej Krzemienski wrote:
> 2017-06-01 1:06 GMT+02:00 Gavin Lambert:
>> On 31/05/2017 20:44, Andrzej Krzemienski wrote:
>>> In your mental model what is the interpretation of the situation when you
>>> have both an error_code and an exception_ptr?
>>
>> Mostly where error() returns the error_code and exception() returns the
>> system_error(error()), so that the caller could choose to treat it either
>> way, as you'd expect.
>>
>> Conceivably there could be cases where someone might want to have a
>> different type of exception (eg. errc::invalid_argument plus
>> std::out_of_range or a derived type, which might convey some additional
>> information), although that could also be a can of worms best left unopened.
> 
> So, are you saying that exception() and error() observe the same "failure
> report", just in two different ways?

Of course.  It's a single object containing the single outcome of a 
method call.  There might be multiple related sub-states but it's still 
a single event with a single result.