Hide server-related APIs behind a feature gate

[Xuanwo]

Hi, I'm working on addressing apache/opendal#5620.

This crate is critical for me, but I only care about the client side and don't want all my users to depend on axum. Would it be possible to hide server-related APIs behind a feature gate instead?

[tclem]

This is a good idea, thanks for opening an issue @Xuanwo. Would you like to take a crack at it and submit a pull request? Otherwise, I can't promise when we'll get around to this as it's low priority for our current project since we always end up with both clients and servers in the same app anyway.

[Xuanwo]

Thank you for the response! I finally implemented the feature by hand since twirp is really simple. I love it 😝

Back to this issue, I will take a look over this when I have time. But I have to declare that it's also not on the top of my task list 😃

[tuxy-streamer]

Dependencies are quite separable between client and server dependencies but the only problem is error.rs as it holds error response for both client as well as the server.
A potential solution is to have two different error response files, 'client_error.rs' and 'server_error.rs' which will help to optionally disable server dependencies completely.

I am happy to send a pull request regarding this issue.