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Subject: Re: [boost] [review] **NEXT WEEK** Review of Outcome (starts Fri-19-May)
From: Andrzej Krzemienski (akrzemi1_at_[hidden])
Date: 2017-05-12 18:00:50

2017-05-12 18:26 GMT+02:00 Niall Douglas via Boost <boost_at_[hidden]>:

> On 12/05/2017 14:13, Jarrad Waterloo via Boost wrote:
> > How does expected work in a world of multiple return value, structured
> bindings?
> I see no reason that they shouldn't work perfectly. Expected provides
> lvalue, const lvalue, rvalue and const rvalue observers. So it should
> just work.
> But I'll admit I haven't tested it. Can you suggest a use case which you
> would like to know if it works with Expected? I can throw together some
> code and see if it works for you.

Or maybe what Jarrad was asking was wether one could write code like this:

outcome<int> fun();

int main()
  auto [val, err] = fun();
  if (err) ...

But if this was the question: outcome cannot be used in this way. For the
same reason as variant<> cannot be used here: because outcome<> can store
only one of - value or error code - at a time: never both.


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