Re: [boost] [outcome] Exception safety guarantees

Andrzej Krzemienski wrote:

``` expected o = fun(); // (*) if (o.has_value()) ... ```

Upon the call to has_value() how is it possible that I am experiencing the valueless_by_exception state?

It's not possible to experience that state here. It's possible to experience it in other scenarios. If o is non-local, for example, the assignment throws, and a catch block either catches the exception and further code examines o, or if the catch block or a destructor calls a function that examines o.