use clap::Parser; #[derive(Parser)] // requires `derive` feature #[command(name = "cargo")] #[command(bin_name = "cargo")] enum CargoCli { ExampleDerive(ExampleDeriveArgs), } #[derive(clap::Args)] #[command(author, version, about, long_about = None)] struct ExampleDeriveArgs { #[arg(long)] manifest_path: Option, } fn main() { let CargoCli::ExampleDerive(args) = CargoCli::parse(); println!("{:?}", args.manifest_path); }