Subject: Re: [boost] [review] Review of Outcome v2 (Fri-19-Jan to Sun-28-Jan, 2018)
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2018-02-01 14:53:08
On 02/01/18 16:40, Jonathan Müller via Boost wrote:
> On 01.02.2018 14:32, Andrey Semashev via Boost wrote:
>> On 02/01/18 15:03, Jonathan Müller via Boost wrote:
>>>
>>> And accessing the value on an optional without checking it should
>>> always be a red flag and not just written "naturally" (That's why
>>> operator-> for optional is a mistake IMO).
>>
>> I disagree. The necessity to write ".value()" on every access to `a`
>> is an overhead, both in user's effort and runtime performance. This,
>> actually, illustrates my point.
>>
>
> With my proposal, `value()` would be the unchecked (i.e. debug checked)
> access, so it has no effort on runtime performance.
If your `value()` is unchecked then I really don't understand how
writing `a.value().foo()` would be less error prone than the current
`a->foo()` without a prior check.
> Yes, it is less convenient than exceptions, that's why you should still
> prefer exceptions without more language support for optionals and
> expected objects.
>
> But I don't think it is more error prone than exceptions, which is the
> point I'm trying to make.
The more code you have to type, the more places where you can make a
mistake. My point is that since with exceptions you don't need to type
any code to test for errors, except where you actually do, it is less
error prone.