Question: how the fields are required by subcommand

[JayiceZ]

Hi, I am new to structopt. And I am not sure is it a structopt issue or a clap issue? Here is the situation I met:

I defined it, like:

struct Opt {
    #[structopt(long)]
    cat: Option<String>,

    #[structopt(long)]
    dog: Option<String>,

    #[structopt(long)]
    host: Option<String>,

    #[structopt(subcommand)]
    cmd: Option<Cmd>,
}

enum Cmd {
    Test {
        #[structopt(long)]
        dir: Option<String>,
    },
    Debug{
        #[structopt(long)]
        remote: Option<String>,
    },
}

And what I want is: When Test SubCommand is set, one of cat and dog should be set(or it means that they are in a Group, and the group is required when Test is set); And when Debug is set, host should be set.

I have read the doc and examples, but I am not sure how to implement this function? 😭

[epage]

From what I've seen so far, clap allows validation of relationship of args and groups but subcommands are effectively in another namespace, preventing them from interacting with that system.

In clap3, there is App::error to create clap-like errors for custom validation. There is also interest in generalizing clap's mechanisms so people are less likely to run into hurdles like this.

[TeXitoi]

This is an enhancement, and structopt is now feature frozen.