大家好，有一个clap库使用请教

#[derive(Parser)]
#[clap(author, about, long_about = None)]
struct Cli {
    #[clap(short, long, value_parser, value_name = "DIRECTORY")]
    directory: Option<PathBuf>,

    #[clap(
        short,
        long,
        visible_short_aliases = ['f'], // -f is used by clash, it is a compatibility option
        value_parser,
        value_name = "FILE",
        default_value = "config.yaml",
        help = "Specify configuration file"
    )]
    config: PathBuf,
    #[clap(
        short = 't',
        long,
        value_parser,
        default_value = "false",
        help = "Test configuration and exit"
    )]
    test_config: bool,
    #[clap(
        short,
        long,
        visible_short_aliases = ['V'],
        value_parser,
        default_value = "false",
        help = "Print clash-rs version and exit"
    )]
    version: bool,
    #[clap(short, long, help = "Additinally log to file")]
    log_file: Option<String>,

    #[clap(
        long,
        value_parser,
        default_value = "false",
        help = "Enable crash report to help improve clash"
    )]
    help_improve: bool,
}

这段代码是来自clash-rs的代码，我在clap官网没有查找到"#[clap]" 这个属性宏的用法，特来请教哈大家，或者可能是在官网哪里我没有发现，希望大家能指点我一下，感谢