clap/clap_derive/examples/arg_enum.rs
Ed Page d840d5650e fix(derive)!: Rename Clap to Parser.
Before #2005, `Clap` was a special trait that derived all clap traits it
detected were relevant (including an enum getting both `ArgEnum`,
`Clap`, and `Subcommand`).  Now, we have elevated `Clap`, `Args`,
`Subcommand`, and `ArgEnum` to be user facing but the name `Clap` isn't
very descriptive.

This also helps further clarify the relationships so a crate providing
an item to be `#[clap(flatten)]` or `#[clap(subcommand)]` is more likely
to choose the needed trait to derive.

Also, my proposed fix fo #2785 includes making `App` attributes almost
exclusively for `Clap`.  Clarifying the names/roles will help
communicate this.

For prior discussion, see #2583
2021-10-09 20:12:03 -05:00

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670 B
Rust

//! Usage example of `arg_enum`
//!
//! All the variants of the enum and the enum itself support `rename_all`
use clap::{ArgEnum, Parser};
#[derive(ArgEnum, Debug, PartialEq, Clone)]
enum ArgChoice {
/// Descriptions are supported as doc-comment
Foo,
// Renames are supported
#[clap(name = "b-a-r")]
Bar,
// Aliases are supported
#[clap(alias = "b", alias = "z")]
Baz,
// Hiding variants from help and completion is supported
#[clap(hidden = true)]
Hidden,
}
#[derive(Parser, PartialEq, Debug)]
struct Opt {
#[clap(arg_enum)]
arg: ArgChoice,
}
fn main() {
let opt = Opt::parse();
println!("{:#?}", opt);
}