Subject: Re: [boost] [outcome] success-or-failure objects
From: Gavin Lambert (gavinl_at_[hidden])
Date: 2018-01-23 22:40:13
On 24/01/2018 11:13, Emil Dotchevski wrote:
>> There's a sizeable number of people who are very keen on doing so. Hence
>> std::logic_error and family i.e. WG21 historically has agreed.
>
> It is unreasonable to think that a program that has just encountered a
> logic error can recover gracefully from it any more it can do so from a
> crash. Try to recover, and you might make things worse, possibly much worse.
Not necessarily. It depends on how well-partitioned things are and how
far-reaching the side effects executed thus far affect other things.
For an example, think of a web browser. At some point it parses some
malformed HTML and sets a property local to the page to null. At some
later point something accesses that property without checking for null
first. This is a logic error, but it's a completely benign and
recoverable one (at least on platforms where memory around null is
guaranteed to be invalid). The browser can recover simply by aborting
the load/render of that page and showing an error, without affecting any
other pages or crashing the browser itself.
Other similar cases exist, where a data structure might be left in an
undefined but still destructible state, but it doesn't matter because
the error recovery process will just destroy that structure anyway.