Well-known-types support

[vladbat00]

Consider the following Service:

service Crow {
    rpc Hello (google.protobuf.Empty) returns (Caw);
}

This is what compiler generates for it:

pub trait Crow {
    fn hello(&mut self, ctx: ::grpcio::RpcContext, req: super::empty::Empty, sink: ::grpcio::UnarySink<super::hello::Caw>);
}

^ And compilation obviously fails, because super has no empty module in its scope.

rust-protobuf seems to have support for well-known-types, and I think it's possible to reuse it. Haven't dug too much into the code, but if I'm not mistaken all the needed modules and methods are public, so maybe it won't be very painful to implement.

[overvenus]

Agree, it is nice to have, would you like to try @mvlabat ?

[vladbat00]

Not having too much free time lately, but if nobody else will, I'll give it a try. Would be glad to help, not sure it'll happen soon though :)

[jessegrosjean]

You can work around this problem by:

1. Generate your proto rust files in a common directory.
2. Adding a mod.rs file to that directory.
3. In that mod.rs file map empty::Empty to protobuf::well_known_types::Empty:

use protobuf;

...proto.rs mods...

mod empty {
  pub use protobuf::well_known_types::Empty;
}