Re: [boost] [outcome] High level summary of review feedback accepted so far

Subject: Re: [boost] [outcome] High level summary of review feedback accepted so far
From: Gavin Lambert (gavinl_at_[hidden])
Date: 2017-05-30 07:40:31

Mere moments ago, quoth I:
> But without that, it's still possible with:
> 
>    if (r.has_error()) { (void) r.value(); /* will throw */ }
> 
> (Slight downside of this is that the compiler has to inline and walk 
> into value() before realising that it always throws, so it might emit 
> warnings unless you add some extra boilerplate.)

Though to be fair, this is a bit contrived in isolation; it's likely 
that code that makes use of that behaviour would more naturally be 
written as:

     auto value = do_something().value();
     // that threw if empty, error, or exception,
     // so now you can safely play with value.

The main point being that I'm not sure how useful it would be to have 
.exception() contain a synthetic exception in the non-thrown cases.

(But then, normally you don't want to catch and transport exceptions at 
all, which is why result<T> exists.  outcome<T> and exception transport 
only becomes useful when you're about to exit from an exception-enabled 
island into a sea of noexcept, to use Niall's phrasing.)