Trait clap::Args

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pub trait Args: FromArgMatches + Sized {
    // Required methods
    fn augment_args(cmd: Command) -> Command;
    fn augment_args_for_update(cmd: Command) -> Command;

    // Provided method
    fn group_id() -> Option<Id> { ... }
}
Expand description

Parse a set of arguments into a user-defined container.

Implementing this trait lets a parent container delegate argument parsing behavior to Self. with:

  • #[command(flatten)] args: ChildArgs: Attribute can only be used with struct fields that impl Args.
  • Variant(ChildArgs): No attribute is used with enum variants that impl Args.

See the derive reference for attributes and best practices.

NOTE: Deriving requires the [derive feature flag][crate::_features]

§Example

#[derive(clap::Parser)]
struct Args {
   #[command(flatten)]
   logging: LogArgs,
}

#[derive(clap::Args)]
struct LogArgs {
   #[arg(long, short = 'v', action = clap::ArgAction::Count)]
   verbose: i8,
}

Required Methods§

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fn augment_args(cmd: Command) -> Command

Append to Command so it can instantiate Self.

See also CommandFactory.

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fn augment_args_for_update(cmd: Command) -> Command

Append to Command so it can update self.

This is used to implement #[command(flatten)]

See also CommandFactory.

Provided Methods§

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fn group_id() -> Option<Id>

Report the ArgGroup::id for this set of arguments

Object Safety§

This trait is not object safe.

Implementations on Foreign Types§

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impl<T: Args> Args for Box<T>

Implementors§