Re: [boost] [next gen future-promise] What to callthemonadicreturntype?

Subject: Re: [boost] [next gen future-promise] What to callthemonadicreturntype?
From: Peter Dimov (lists_at_[hidden])
Date: 2015-05-30 16:49:04

Vicente J. Botet Escriba wrote:
> >> Surely for catch_error() one must always return the same type of future 
> >> as the input? Otherwise it couldn't work when f1 has a value.
> >
> > Vicente in N4048 says that it's not required to return the same type.
> >
> If I said that it was an error. Could you point me where?

Input Parameters:
• Lambda function: The lambda function on map()/bind() takes a 
future<t>::value_type. The lambda
function on catch_error() takes an exception_ptr. Both could return whatever 
type. This makes propagating
exceptions straightforward. This approach also simplifies the chaining of 
continuations.