Re: [boost] Final lightweight monad, next gen futures and upcoming AFIO review

On 6/28/2015 5:02 PM, Vinícius dos Santos Oliveira wrote:

2015-06-28 17:52 GMT-03:00 Vinícius dos Santos Oliveira < vini.ipsmaker@gmail.com>:

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2015-06-28 17:52 GMT-03:00 Niall Douglas :

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monad<T>, result<T> and option<T> are all *synchronous* value transports. Just like Rust's Result and Option.

So, why can result<t> be empty?

I mean: result is like "give me T or it's an error". There is no empty state. Empty would already be an error state. I'd only understand empty if it's an async operation that didn't finish already.

What's the state of a default constructed result? Is it an error state? Is it empty? Or is it not default constructible?