+1 This is also similar to how errors are typed in Go as well.
On Wednesday, April 6, 2016, Alexander Rojas <alexan...@mesosphere.io> wrote: > +1 > > What I like is that it allows from some kind of type safety into the error > management beyond trying to parse error strings. > > > On 05 Apr 2016, at 03:48, Michael Park <mp...@apache.org <javascript:;>> > wrote: > > > > Contrary to standard C++ practices, Mesos uses return values as the > > mechanism > > for error handling rather than exceptions. > > > > This proposal is simply an evolution of the current mechanism we have in > > Mesos today. > > This direction is consistent with the designs made in Rust, which uses > > return values as > > the error handling mechanism at the language level. > > > > The first step is to add an additional template parameter to class > template > > *Try*, to get *Try<T, E>*. > > > > The proposed design defaults* E *to *Error*, and requires that *E* be, or > > is inherited from *Error*. > > The return type of *error()* is *const std::string&* if *E == Error* and > > *const E&* otherwise, > > for backwards-compatibility reasons. > > > > So in the end, *Try<T>* behaves exactly as before. > > > > The work is being tracked in MESOS-5107 > > <https://issues.apache.org/jira/browse/MESOS-5107>, and i've written a > > quick design doc > > < > https://docs.google.com/document/d/1tG21sD-ZX64FHAKJwhEPk6JkgsBIv12AmA1Y3J0kCYY/edit# > > > > capturing > > some of the preliminary thoughts on this topic, and a proposal for an > > immediate use case > > for the Windows work. > > > > If you're interested in how Rust deals with error handling, check out > > https://doc.rust-lang.org/book/error-handling.html. Our *Option* is > their > > *Option*, > > our *Try* is their *Result*, and they don't have our *Result*. > > > > I'm going to be pushing the changes proposed shortly, but the changes are > > small and > > does not require a large sweeping changes or anything like that. > > So please reach out to me with your concerns and complaints and I will be > > sure to address them. > > > > Thanks, > > > > MPark > > -- ~Kevin
