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    #![cfg_attr(not(feature = "usage"), allow(unused_mut))]

    // Std
    use std::env;
    use std::ffi::OsString;
    use std::fmt;
    use std::io;
    use std::ops::Index;
    use std::path::Path;

    // Internal
    use crate::builder::app_settings::{AppFlags, AppSettings};
    use crate::builder::arg_settings::ArgSettings;
    use crate::builder::ArgAction;
    use crate::builder::IntoResettable;
    use crate::builder::PossibleValue;
    use crate::builder::Str;
    use crate::builder::StyledStr;
    use crate::builder::{Arg, ArgGroup, ArgPredicate};
    use crate::error::ErrorKind;
    use crate::error::Result as ClapResult;
    use crate::mkeymap::MKeyMap;
    use crate::output::fmt::Stream;
    use crate::output::{fmt::Colorizer, write_help, Usage};
    use crate::parser::{ArgMatcher, ArgMatches, Parser};
    use crate::util::ChildGraph;
    use crate::util::FlatMap;
    use crate::util::{color::ColorChoice, Id};
    use crate::{Error, INTERNAL_ERROR_MSG};

    #[cfg(debug_assertions)]
    use crate::builder::debug_asserts::assert_app;

    /// Build a command-line interface.
    ///
    /// This includes defining arguments, subcommands, parser behavior, and help output.
    /// Once all configuration is complete,
    /// the [`Command::get_matches`] family of methods starts the runtime-parsing
    /// process. These methods then return information about the user supplied
    /// arguments (or lack thereof).
    ///
    /// When deriving a [`Parser`][crate::Parser], you can use
    /// [`CommandFactory::command`][crate::CommandFactory::command] to access the
    /// `Command`.
    ///
    /// - [Basic API][crate::Command#basic-api]
    /// - [Application-wide Settings][crate::Command#application-wide-settings]
    /// - [Command-specific Settings][crate::Command#command-specific-settings]
    /// - [Subcommand-specific Settings][crate::Command#subcommand-specific-settings]
    /// - [Reflection][crate::Command#reflection]
    ///
    /// # Examples
    ///
    /// ```no_run
    /// # use clap::{Command, Arg};
    /// let m = Command::new("My Program")
    ///     .author("Me, me@mail.com")
    ///     .version("1.0.2")
    ///     .about("Explains in brief what the program does")
    ///     .arg(
    ///         Arg::new("in_file")
    ///     )
    ///     .after_help("Longer explanation to appear after the options when \
    ///                  displaying the help information from --help or -h")
    ///     .get_matches();
    ///
    /// // Your program logic starts here...
    /// ```
    /// [`Command::get_matches`]: Command::get_matches()
    #[derive(Debug, Clone)]
    pub struct Command {
        name: Str,
        long_flag: Option<Str>,
        short_flag: Option<char>,
        display_name: Option<String>,
        bin_name: Option<String>,
        author: Option<Str>,
        version: Option<Str>,
        long_version: Option<Str>,
        about: Option<StyledStr>,
        long_about: Option<StyledStr>,
        before_help: Option<StyledStr>,
        before_long_help: Option<StyledStr>,
        after_help: Option<StyledStr>,
        after_long_help: Option<StyledStr>,
        aliases: Vec<(Str, bool)>,             // (name, visible)
        short_flag_aliases: Vec<(char, bool)>, // (name, visible)
        long_flag_aliases: Vec<(Str, bool)>,   // (name, visible)
        usage_str: Option<StyledStr>,
        usage_name: Option<String>,
        help_str: Option<StyledStr>,
        disp_ord: Option<usize>,
        term_w: Option<usize>,
        max_w: Option<usize>,
        #[cfg(feature = "help")]
        template: Option<StyledStr>,
        settings: AppFlags,
        g_settings: AppFlags,
        args: MKeyMap,
        subcommands: Vec<Command>,
        replacers: FlatMap<Str, Vec<Str>>,
        groups: Vec<ArgGroup>,
        current_help_heading: Option<Str>,
        current_disp_ord: Option<usize>,
        subcommand_value_name: Option<Str>,
        subcommand_heading: Option<Str>,
        external_value_parser: Option<super::ValueParser>,
        long_help_exists: bool,
    }

    /// # Basic API
    impl Command {
        /// Creates a new instance of an `Command`.
        ///
        /// It is common, but not required, to use binary name as the `name`. This
        /// name will only be displayed to the user when they request to print
        /// version or help and usage information.
        ///
        /// See also [`command!`](crate::command!) and [`crate_name!`](crate::crate_name!).
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("My Program")
        /// # ;
        /// ```
        pub fn new(name: impl Into<Str>) -> Self {
            /// The actual implementation of `new`, non-generic to save code size.
            ///
            /// If we don't do this rustc will unnecessarily generate multiple versions
            /// of this code.
            fn new_inner(name: Str) -> Command {
                Command {
                    name,
                    ..Default::default()
                }
            }

            new_inner(name.into())
        }

        /// Adds an [argument] to the list of valid possibilities.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, arg, Arg};
        /// Command::new("myprog")
        ///     // Adding a single "flag" argument with a short and help text, using Arg::new()
        ///     .arg(
        ///         Arg::new("debug")
        ///            .short('d')
        ///            .help("turns on debugging mode")
        ///     )
        ///     // Adding a single "option" argument with a short, a long, and help text using the less
        ///     // verbose Arg::from()
        ///     .arg(
        ///         arg!(-c --config <CONFIG> "Optionally sets a config file to use")
        ///     )
        /// # ;
        /// ```
        /// [argument]: Arg
        #[must_use]
        pub fn arg(mut self, a: impl Into<Arg>) -> Self {
            let arg = a.into();
            self.arg_internal(arg);
            self
        }

        fn arg_internal(&mut self, mut arg: Arg) {
            if let Some(current_disp_ord) = self.current_disp_ord.as_mut() {
                if !arg.is_positional() {
                    let current = *current_disp_ord;
                    arg.disp_ord.get_or_insert(current);
                    *current_disp_ord = current + 1;
                }
            }

            arg.help_heading
                .get_or_insert_with(|| self.current_help_heading.clone());
            self.args.push(arg);
        }

        /// Adds multiple [arguments] to the list of valid possibilities.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, arg, Arg};
        /// Command::new("myprog")
        ///     .args([
        ///         arg!("[debug] -d 'turns on debugging info'"),
        ///         Arg::new("input").help("the input file to use")
        ///     ])
        /// # ;
        /// ```
        /// [arguments]: Arg
        #[must_use]
        pub fn args(mut self, args: impl IntoIterator<Item = impl Into<Arg>>) -> Self {
            for arg in args {
                self = self.arg(arg);
            }
            self
        }

        /// Allows one to mutate an [`Arg`] after it's been added to a [`Command`].
        ///
        /// This can be useful for modifying the auto-generated help or version arguments.
        ///
        /// # Panics
        ///
        /// If the argument is undefined
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgAction};
        ///
        /// let mut cmd = Command::new("foo")
        ///     .arg(Arg::new("bar")
        ///         .short('b')
        ///         .action(ArgAction::SetTrue))
        ///     .mut_arg("bar", |a| a.short('B'));
        ///
        /// let res = cmd.try_get_matches_from_mut(vec!["foo", "-b"]);
        ///
        /// // Since we changed `bar`'s short to "B" this should err as there
        /// // is no `-b` anymore, only `-B`
        ///
        /// assert!(res.is_err());
        ///
        /// let res = cmd.try_get_matches_from_mut(vec!["foo", "-B"]);
        /// assert!(res.is_ok());
        /// ```
        #[must_use]
        #[cfg_attr(debug_assertions, track_caller)]
        pub fn mut_arg<F>(mut self, arg_id: impl AsRef<str>, f: F) -> Self
        where
            F: FnOnce(Arg) -> Arg,
        {
            let id = arg_id.as_ref();
            let a = self
                .args
                .remove_by_name(id)
                .unwrap_or_else(|| panic!("Argument `{}` is undefined", id));

            self.args.push(f(a));
            self
        }

        /// Allows one to mutate a [`Command`] after it's been added as a subcommand.
        ///
        /// This can be useful for modifying auto-generated arguments of nested subcommands with
        /// [`Command::mut_arg`].
        ///
        /// # Panics
        ///
        /// If the subcommand is undefined
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::Command;
        ///
        /// let mut cmd = Command::new("foo")
        ///         .subcommand(Command::new("bar"))
        ///         .mut_subcommand("bar", |subcmd| subcmd.disable_help_flag(true));
        ///
        /// let res = cmd.try_get_matches_from_mut(vec!["foo", "bar", "--help"]);
        ///
        /// // Since we disabled the help flag on the "bar" subcommand, this should err.
        ///
        /// assert!(res.is_err());
        ///
        /// let res = cmd.try_get_matches_from_mut(vec!["foo", "bar"]);
        /// assert!(res.is_ok());
        /// ```
        #[must_use]
        pub fn mut_subcommand<F>(mut self, name: impl AsRef<str>, f: F) -> Self
        where
            F: FnOnce(Self) -> Self,
        {
            let name = name.as_ref();
            let pos = self.subcommands.iter().position(|s| s.name == name);

            let subcmd = if let Some(idx) = pos {
                self.subcommands.remove(idx)
            } else {
                panic!("Command `{}` is undefined", name)
            };

            self.subcommands.push(f(subcmd));
            self
        }

        /// Adds an [`ArgGroup`] to the application.
        ///
        /// [`ArgGroup`]s are a family of related arguments.
        /// By placing them in a logical group, you can build easier requirement and exclusion rules.
        ///
        /// Example use cases:
        /// - Make an entire [`ArgGroup`] required, meaning that one (and *only*
        ///   one) argument from that group must be present at runtime.
        /// - Name an [`ArgGroup`] as a conflict to another argument.
        ///   Meaning any of the arguments that belong to that group will cause a failure if present with
        ///   the conflicting argument.
        /// - Ensure exclusion between arguments.
        /// - Extract a value from a group instead of determining exactly which argument was used.
        ///
        /// # Examples
        ///
        /// The following example demonstrates using an [`ArgGroup`] to ensure that one, and only one,
        /// of the arguments from the specified group is present at runtime.
        ///
        /// ```no_run
        /// # use clap::{Command, arg, ArgGroup};
        /// Command::new("cmd")
        ///     .arg(arg!("--set-ver [ver] 'set the version manually'"))
        ///     .arg(arg!("--major 'auto increase major'"))
        ///     .arg(arg!("--minor 'auto increase minor'"))
        ///     .arg(arg!("--patch 'auto increase patch'"))
        ///     .group(ArgGroup::new("vers")
        ///          .args(["set-ver", "major", "minor","patch"])
        ///          .required(true))
        /// # ;
        /// ```
        #[inline]
        #[must_use]
        pub fn group(mut self, group: impl Into<ArgGroup>) -> Self {
            self.groups.push(group.into());
            self
        }

        /// Adds multiple [`ArgGroup`]s to the [`Command`] at once.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, arg, ArgGroup};
        /// Command::new("cmd")
        ///     .arg(arg!("--set-ver [ver] 'set the version manually'"))
        ///     .arg(arg!("--major         'auto increase major'"))
        ///     .arg(arg!("--minor         'auto increase minor'"))
        ///     .arg(arg!("--patch         'auto increase patch'"))
        ///     .arg(arg!("-c [FILE]       'a config file'"))
        ///     .arg(arg!("-i [IFACE]      'an interface'"))
        ///     .groups([
        ///         ArgGroup::new("vers")
        ///             .args(["set-ver", "major", "minor","patch"])
        ///             .required(true),
        ///         ArgGroup::new("input")
        ///             .args(["c", "i"])
        ///     ])
        /// # ;
        /// ```
        #[must_use]
        pub fn groups(mut self, groups: impl IntoIterator<Item = impl Into<ArgGroup>>) -> Self {
            for g in groups.into_iter() {
                self = self.group(g.into());
            }
            self
        }

        /// Adds a subcommand to the list of valid possibilities.
        ///
        /// Subcommands are effectively sub-[`Command`]s, because they can contain their own arguments,
        /// subcommands, version, usage, etc. They also function just like [`Command`]s, in that they get
        /// their own auto generated help, version, and usage.
        ///
        /// A subcommand's [`Command::name`] will be used for:
        /// - The argument the user passes in
        /// - Programmatically looking up the subcommand
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, arg};
        /// Command::new("myprog")
        ///     .subcommand(Command::new("config")
        ///         .about("Controls configuration features")
        ///         .arg(arg!("<config> 'Required configuration file to use'")))
        /// # ;
        /// ```
        #[inline]
        #[must_use]
        pub fn subcommand(self, subcmd: impl Into<Command>) -> Self {
            let subcmd = subcmd.into();
            self.subcommand_internal(subcmd)
        }

        fn subcommand_internal(mut self, mut subcmd: Self) -> Self {
            if let Some(current_disp_ord) = self.current_disp_ord.as_mut() {
                let current = *current_disp_ord;
                subcmd.disp_ord.get_or_insert(current);
                *current_disp_ord = current + 1;
            }
            self.subcommands.push(subcmd);
            self
        }

        /// Adds multiple subcommands to the list of valid possibilities.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg, };
        /// # Command::new("myprog")
        /// .subcommands( [
        ///        Command::new("config").about("Controls configuration functionality")
        ///                                 .arg(Arg::new("config_file")),
        ///        Command::new("debug").about("Controls debug functionality")])
        /// # ;
        /// ```
        /// [`IntoIterator`]: std::iter::IntoIterator
        #[must_use]
        pub fn subcommands(mut self, subcmds: impl IntoIterator<Item = impl Into<Self>>) -> Self {
            for subcmd in subcmds {
                self = self.subcommand(subcmd);
            }
            self
        }

        /// Catch problems earlier in the development cycle.
        ///
        /// Most error states are handled as asserts under the assumption they are programming mistake
        /// and not something to handle at runtime.  Rather than relying on tests (manual or automated)
        /// that exhaustively test your CLI to ensure the asserts are evaluated, this will run those
        /// asserts in a way convenient for running as a test.
        ///
        /// **Note::** This will not help with asserts in [`ArgMatches`], those will need exhaustive
        /// testing of your CLI.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgAction};
        /// fn cmd() -> Command {
        ///     Command::new("foo")
        ///         .arg(
        ///             Arg::new("bar").short('b').action(ArgAction::SetTrue)
        ///         )
        /// }
        ///
        /// #[test]
        /// fn verify_app() {
        ///     cmd().debug_assert();
        /// }
        ///
        /// fn main() {
        ///     let m = cmd().get_matches_from(vec!["foo", "-b"]);
        ///     println!("{}", *m.get_one::<bool>("bar").expect("defaulted by clap"));
        /// }
        /// ```
        pub fn debug_assert(mut self) {
            self.build();
        }

        /// Custom error message for post-parsing validation
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, error::ErrorKind};
        /// let mut cmd = Command::new("myprog");
        /// let err = cmd.error(ErrorKind::InvalidValue, "Some failure case");
        /// ```
        pub fn error(&mut self, kind: ErrorKind, message: impl std::fmt::Display) -> Error {
            Error::raw(kind, message).format(self)
        }

        /// Parse [`env::args_os`], exiting on failure.
        ///
        /// # Panics
        ///
        /// If contradictory arguments or settings exist.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// let matches = Command::new("myprog")
        ///     // Args and options go here...
        ///     .get_matches();
        /// ```
        /// [`env::args_os`]: std::env::args_os()
        /// [`Command::try_get_matches_from_mut`]: Command::try_get_matches_from_mut()
        #[inline]
        pub fn get_matches(self) -> ArgMatches {
            self.get_matches_from(env::args_os())
        }

        /// Parse [`env::args_os`], exiting on failure.
        ///
        /// Like [`Command::get_matches`] but doesn't consume the `Command`.
        ///
        /// # Panics
        ///
        /// If contradictory arguments or settings exist.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// let mut cmd = Command::new("myprog")
        ///     // Args and options go here...
        ///     ;
        /// let matches = cmd.get_matches_mut();
        /// ```
        /// [`env::args_os`]: std::env::args_os()
        /// [`Command::get_matches`]: Command::get_matches()
        pub fn get_matches_mut(&mut self) -> ArgMatches {
            self.try_get_matches_from_mut(&mut env::args_os())
                .unwrap_or_else(|e| e.exit())
        }

        /// Parse [`env::args_os`], returning a [`clap::Result`] on failure.
        ///
        /// **NOTE:** This method WILL NOT exit when `--help` or `--version` (or short versions) are
        /// used. It will return a [`clap::Error`], where the [`kind`] is a
        /// [`ErrorKind::DisplayHelp`] or [`ErrorKind::DisplayVersion`] respectively. You must call
        /// [`Error::exit`] or perform a [`std::process::exit`].
        ///
        /// # Panics
        ///
        /// If contradictory arguments or settings exist.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// let matches = Command::new("myprog")
        ///     // Args and options go here...
        ///     .try_get_matches()
        ///     .unwrap_or_else(|e| e.exit());
        /// ```
        /// [`env::args_os`]: std::env::args_os()
        /// [`Error::exit`]: crate::Error::exit()
        /// [`std::process::exit`]: std::process::exit()
        /// [`clap::Result`]: Result
        /// [`clap::Error`]: crate::Error
        /// [`kind`]: crate::Error
        /// [`ErrorKind::DisplayHelp`]: crate::error::ErrorKind::DisplayHelp
        /// [`ErrorKind::DisplayVersion`]: crate::error::ErrorKind::DisplayVersion
        #[inline]
        pub fn try_get_matches(self) -> ClapResult<ArgMatches> {
            // Start the parsing
            self.try_get_matches_from(env::args_os())
        }

        /// Parse the specified arguments, exiting on failure.
        ///
        /// **NOTE:** The first argument will be parsed as the binary name unless
        /// [`Command::no_binary_name`] is used.
        ///
        /// # Panics
        ///
        /// If contradictory arguments or settings exist.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// let arg_vec = vec!["my_prog", "some", "args", "to", "parse"];
        ///
        /// let matches = Command::new("myprog")
        ///     // Args and options go here...
        ///     .get_matches_from(arg_vec);
        /// ```
        /// [`Command::get_matches`]: Command::get_matches()
        /// [`clap::Result`]: Result
        /// [`Vec`]: std::vec::Vec
        pub fn get_matches_from<I, T>(mut self, itr: I) -> ArgMatches
        where
            I: IntoIterator<Item = T>,
            T: Into<OsString> + Clone,
        {
            self.try_get_matches_from_mut(itr).unwrap_or_else(|e| {
                drop(self);
                e.exit()
            })
        }

        /// Parse the specified arguments, returning a [`clap::Result`] on failure.
        ///
        /// **NOTE:** This method WILL NOT exit when `--help` or `--version` (or short versions) are
        /// used. It will return a [`clap::Error`], where the [`kind`] is a [`ErrorKind::DisplayHelp`]
        /// or [`ErrorKind::DisplayVersion`] respectively. You must call [`Error::exit`] or
        /// perform a [`std::process::exit`] yourself.
        ///
        /// **NOTE:** The first argument will be parsed as the binary name unless
        /// [`Command::no_binary_name`] is used.
        ///
        /// # Panics
        ///
        /// If contradictory arguments or settings exist.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// let arg_vec = vec!["my_prog", "some", "args", "to", "parse"];
        ///
        /// let matches = Command::new("myprog")
        ///     // Args and options go here...
        ///     .try_get_matches_from(arg_vec)
        ///     .unwrap_or_else(|e| e.exit());
        /// ```
        /// [`Command::get_matches_from`]: Command::get_matches_from()
        /// [`Command::try_get_matches`]: Command::try_get_matches()
        /// [`Error::exit`]: crate::Error::exit()
        /// [`std::process::exit`]: std::process::exit()
        /// [`clap::Error`]: crate::Error
        /// [`Error::exit`]: crate::Error::exit()
        /// [`kind`]: crate::Error
        /// [`ErrorKind::DisplayHelp`]: crate::error::ErrorKind::DisplayHelp
        /// [`ErrorKind::DisplayVersion`]: crate::error::ErrorKind::DisplayVersion
        /// [`clap::Result`]: Result
        pub fn try_get_matches_from<I, T>(mut self, itr: I) -> ClapResult<ArgMatches>
        where
            I: IntoIterator<Item = T>,
            T: Into<OsString> + Clone,
        {
            self.try_get_matches_from_mut(itr)
        }

        /// Parse the specified arguments, returning a [`clap::Result`] on failure.
        ///
        /// Like [`Command::try_get_matches_from`] but doesn't consume the `Command`.
        ///
        /// **NOTE:** This method WILL NOT exit when `--help` or `--version` (or short versions) are
        /// used. It will return a [`clap::Error`], where the [`kind`] is a [`ErrorKind::DisplayHelp`]
        /// or [`ErrorKind::DisplayVersion`] respectively. You must call [`Error::exit`] or
        /// perform a [`std::process::exit`] yourself.
        ///
        /// **NOTE:** The first argument will be parsed as the binary name unless
        /// [`Command::no_binary_name`] is used.
        ///
        /// # Panics
        ///
        /// If contradictory arguments or settings exist.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// let arg_vec = vec!["my_prog", "some", "args", "to", "parse"];
        ///
        /// let mut cmd = Command::new("myprog");
        ///     // Args and options go here...
        /// let matches = cmd.try_get_matches_from_mut(arg_vec)
        ///     .unwrap_or_else(|e| e.exit());
        /// ```
        /// [`Command::try_get_matches_from`]: Command::try_get_matches_from()
        /// [`clap::Result`]: Result
        /// [`clap::Error`]: crate::Error
        /// [`kind`]: crate::Error
        pub fn try_get_matches_from_mut<I, T>(&mut self, itr: I) -> ClapResult<ArgMatches>
        where
            I: IntoIterator<Item = T>,
            T: Into<OsString> + Clone,
        {
            let mut raw_args = clap_lex::RawArgs::new(itr.into_iter());
            let mut cursor = raw_args.cursor();

            if self.settings.is_set(AppSettings::Multicall) {
                if let Some(argv0) = raw_args.next_os(&mut cursor) {
                    let argv0 = Path::new(&argv0);
                    if let Some(command) = argv0.file_stem().and_then(|f| f.to_str()) {
                        // Stop borrowing command so we can get another mut ref to it.
                        let command = command.to_owned();
                        debug!(
                            "Command::try_get_matches_from_mut: Parsed command {} from argv",
                            command
                        );

                        debug!("Command::try_get_matches_from_mut: Reinserting command into arguments so subcommand parser matches it");
                        raw_args.insert(&cursor, [&command]);
                        debug!("Command::try_get_matches_from_mut: Clearing name and bin_name so that displayed command name starts with applet name");
                        self.name = "".into();
                        self.bin_name = None;
                        return self._do_parse(&mut raw_args, cursor);
                    }
                }
            };

            // Get the name of the program (argument 1 of env::args()) and determine the
            // actual file
            // that was used to execute the program. This is because a program called
            // ./target/release/my_prog -a
            // will have two arguments, './target/release/my_prog', '-a' but we don't want
            // to display
            // the full path when displaying help messages and such
            if !self.settings.is_set(AppSettings::NoBinaryName) {
                if let Some(name) = raw_args.next_os(&mut cursor) {
                    let p = Path::new(name);

                    if let Some(f) = p.file_name() {
                        if let Some(s) = f.to_str() {
                            if self.bin_name.is_none() {
                                self.bin_name = Some(s.to_owned());
                            }
                        }
                    }
                }
            }

            self._do_parse(&mut raw_args, cursor)
        }

        /// Prints the short help message (`-h`) to [`io::stdout()`].
        ///
        /// See also [`Command::print_long_help`].
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::Command;
        /// let mut cmd = Command::new("myprog");
        /// cmd.print_help();
        /// ```
        /// [`io::stdout()`]: std::io::stdout()
        pub fn print_help(&mut self) -> io::Result<()> {
            self._build_self(false);
            let color = self.color_help();

            let mut styled = StyledStr::new();
            let usage = Usage::new(self);
            write_help(&mut styled, self, &usage, false);

            let c = Colorizer::new(Stream::Stdout, color).with_content(styled);
            c.print()
        }

        /// Prints the long help message (`--help`) to [`io::stdout()`].
        ///
        /// See also [`Command::print_help`].
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::Command;
        /// let mut cmd = Command::new("myprog");
        /// cmd.print_long_help();
        /// ```
        /// [`io::stdout()`]: std::io::stdout()
        /// [`BufWriter`]: std::io::BufWriter
        /// [`-h` (short)]: Arg::help()
        /// [`--help` (long)]: Arg::long_help()
        pub fn print_long_help(&mut self) -> io::Result<()> {
            self._build_self(false);
            let color = self.color_help();

            let mut styled = StyledStr::new();
            let usage = Usage::new(self);
            write_help(&mut styled, self, &usage, true);

            let c = Colorizer::new(Stream::Stdout, color).with_content(styled);
            c.print()
        }

        /// Render the short help message (`-h`) to a [`StyledStr`]
        ///
        /// See also [`Command::render_long_help`].
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::Command;
        /// use std::io;
        /// let mut cmd = Command::new("myprog");
        /// let mut out = io::stdout();
        /// let help = cmd.render_help();
        /// println!("{}", help);
        /// ```
        /// [`io::Write`]: std::io::Write
        /// [`-h` (short)]: Arg::help()
        /// [`--help` (long)]: Arg::long_help()
        pub fn render_help(&mut self) -> StyledStr {
            self._build_self(false);

            let mut styled = StyledStr::new();
            let usage = Usage::new(self);
            write_help(&mut styled, self, &usage, false);
            styled
        }

        /// Render the long help message (`--help`) to a [`StyledStr`].
        ///
        /// See also [`Command::render_help`].
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::Command;
        /// use std::io;
        /// let mut cmd = Command::new("myprog");
        /// let mut out = io::stdout();
        /// let help = cmd.render_long_help();
        /// println!("{}", help);
        /// ```
        /// [`io::Write`]: std::io::Write
        /// [`-h` (short)]: Arg::help()
        /// [`--help` (long)]: Arg::long_help()
        pub fn render_long_help(&mut self) -> StyledStr {
            self._build_self(false);

            let mut styled = StyledStr::new();
            let usage = Usage::new(self);
            write_help(&mut styled, self, &usage, true);
            styled
        }

        #[doc(hidden)]
        #[cfg_attr(
            feature = "deprecated",
            deprecated(since = "4.0.0", note = "Replaced with `Command::render_help`")
        )]
        pub fn write_help<W: io::Write>(&mut self, w: &mut W) -> io::Result<()> {
            self._build_self(false);

            let mut styled = StyledStr::new();
            let usage = Usage::new(self);
            write_help(&mut styled, self, &usage, false);
            ok!(write!(w, "{}", styled));
            w.flush()
        }

        #[doc(hidden)]
        #[cfg_attr(
            feature = "deprecated",
            deprecated(since = "4.0.0", note = "Replaced with `Command::render_long_help`")
        )]
        pub fn write_long_help<W: io::Write>(&mut self, w: &mut W) -> io::Result<()> {
            self._build_self(false);

            let mut styled = StyledStr::new();
            let usage = Usage::new(self);
            write_help(&mut styled, self, &usage, true);
            ok!(write!(w, "{}", styled));
            w.flush()
        }

        /// Version message rendered as if the user ran `-V`.
        ///
        /// See also [`Command::render_long_version`].
        ///
        /// ### Coloring
        ///
        /// This function does not try to color the message nor it inserts any [ANSI escape codes].
        ///
        /// ### Examples
        ///
        /// ```rust
        /// # use clap::Command;
        /// use std::io;
        /// let cmd = Command::new("myprog");
        /// println!("{}", cmd.render_version());
        /// ```
        /// [`io::Write`]: std::io::Write
        /// [`-V` (short)]: Command::version()
        /// [`--version` (long)]: Command::long_version()
        /// [ANSI escape codes]: https://en.wikipedia.org/wiki/ANSI_escape_code
        pub fn render_version(&self) -> String {
            self._render_version(false)
        }

        /// Version message rendered as if the user ran `--version`.
        ///
        /// See also [`Command::render_version`].
        ///
        /// ### Coloring
        ///
        /// This function does not try to color the message nor it inserts any [ANSI escape codes].
        ///
        /// ### Examples
        ///
        /// ```rust
        /// # use clap::Command;
        /// use std::io;
        /// let cmd = Command::new("myprog");
        /// println!("{}", cmd.render_long_version());
        /// ```
        /// [`io::Write`]: std::io::Write
        /// [`-V` (short)]: Command::version()
        /// [`--version` (long)]: Command::long_version()
        /// [ANSI escape codes]: https://en.wikipedia.org/wiki/ANSI_escape_code
        pub fn render_long_version(&self) -> String {
            self._render_version(true)
        }

        /// Usage statement
        ///
        /// ### Examples
        ///
        /// ```rust
        /// # use clap::Command;
        /// use std::io;
        /// let mut cmd = Command::new("myprog");
        /// println!("{}", cmd.render_usage());
        /// ```
        pub fn render_usage(&mut self) -> StyledStr {
            self.render_usage_().unwrap_or_default()
        }

        pub(crate) fn render_usage_(&mut self) -> Option<StyledStr> {
            // If there are global arguments, or settings we need to propagate them down to subcommands
            // before parsing incase we run into a subcommand
            self._build_self(false);

            Usage::new(self).create_usage_with_title(&[])
        }
    }

    /// # Application-wide Settings
    ///
    /// These settings will apply to the top-level command and all subcommands, by default.  Some
    /// settings can be overridden in subcommands.
    impl Command {
        /// Specifies that the parser should not assume the first argument passed is the binary name.
        ///
        /// This is normally the case when using a "daemon" style mode.  For shells / REPLs, see
        /// [`Command::multicall`][Command::multicall].
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, arg};
        /// let m = Command::new("myprog")
        ///     .no_binary_name(true)
        ///     .arg(arg!(<cmd> ... "commands to run"))
        ///     .get_matches_from(vec!["command", "set"]);
        ///
        /// let cmds: Vec<_> = m.get_many::<String>("cmd").unwrap().collect();
        /// assert_eq!(cmds, ["command", "set"]);
        /// ```
        /// [`try_get_matches_from_mut`]: crate::Command::try_get_matches_from_mut()
        #[inline]
        pub fn no_binary_name(self, yes: bool) -> Self {
            if yes {
                self.global_setting(AppSettings::NoBinaryName)
            } else {
                self.unset_global_setting(AppSettings::NoBinaryName)
            }
        }

        /// Try not to fail on parse errors, like missing option values.
        ///
        /// **NOTE:** This choice is propagated to all child subcommands.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, arg};
        /// let cmd = Command::new("cmd")
        ///   .ignore_errors(true)
        ///   .arg(arg!(-c --config <FILE> "Sets a custom config file"))
        ///   .arg(arg!(-x --stuff <FILE> "Sets a custom stuff file"))
        ///   .arg(arg!(f: -f "Flag"));
        ///
        /// let r = cmd.try_get_matches_from(vec!["cmd", "-c", "file", "-f", "-x"]);
        ///
        /// assert!(r.is_ok(), "unexpected error: {:?}", r);
        /// let m = r.unwrap();
        /// assert_eq!(m.get_one::<String>("config").unwrap(), "file");
        /// assert!(*m.get_one::<bool>("f").expect("defaulted"));
        /// assert_eq!(m.get_one::<String>("stuff"), None);
        /// ```
        #[inline]
        pub fn ignore_errors(self, yes: bool) -> Self {
            if yes {
                self.global_setting(AppSettings::IgnoreErrors)
            } else {
                self.unset_global_setting(AppSettings::IgnoreErrors)
            }
        }

        /// Replace prior occurrences of arguments rather than error
        ///
        /// For any argument that would conflict with itself by default (e.g.
        /// [`ArgAction::Set`][ArgAction::Set], it will now override itself.
        ///
        /// This is the equivalent to saying the `foo` arg using [`Arg::overrides_with("foo")`] for all
        /// defined arguments.
        ///
        /// **NOTE:** This choice is propagated to all child subcommands.
        ///
        /// [`Arg::overrides_with("foo")`]: crate::Arg::overrides_with()
        #[inline]
        pub fn args_override_self(self, yes: bool) -> Self {
            if yes {
                self.global_setting(AppSettings::AllArgsOverrideSelf)
            } else {
                self.unset_global_setting(AppSettings::AllArgsOverrideSelf)
            }
        }

        /// Disables the automatic delimiting of values after `--` or when [`Command::trailing_var_arg`]
        /// was used.
        ///
        /// **NOTE:** The same thing can be done manually by setting the final positional argument to
        /// [`Arg::value_delimiter(None)`]. Using this setting is safer, because it's easier to locate
        /// when making changes.
        ///
        /// **NOTE:** This choice is propagated to all child subcommands.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// Command::new("myprog")
        ///     .dont_delimit_trailing_values(true)
        ///     .get_matches();
        /// ```
        ///
        /// [`Arg::value_delimiter(None)`]: crate::Arg::value_delimiter()
        #[inline]
        pub fn dont_delimit_trailing_values(self, yes: bool) -> Self {
            if yes {
                self.global_setting(AppSettings::DontDelimitTrailingValues)
            } else {
                self.unset_global_setting(AppSettings::DontDelimitTrailingValues)
            }
        }

        /// Sets when to color output.
        ///
        /// **NOTE:** This choice is propagated to all child subcommands.
        ///
        /// **NOTE:** Default behaviour is [`ColorChoice::Auto`].
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, ColorChoice};
        /// Command::new("myprog")
        ///     .color(ColorChoice::Never)
        ///     .get_matches();
        /// ```
        /// [`ColorChoice::Auto`]: crate::ColorChoice::Auto
        #[cfg(feature = "color")]
        #[inline]
        #[must_use]
        pub fn color(self, color: ColorChoice) -> Self {
            let cmd = self
                .unset_global_setting(AppSettings::ColorAuto)
                .unset_global_setting(AppSettings::ColorAlways)
                .unset_global_setting(AppSettings::ColorNever);
            match color {
                ColorChoice::Auto => cmd.global_setting(AppSettings::ColorAuto),
                ColorChoice::Always => cmd.global_setting(AppSettings::ColorAlways),
                ColorChoice::Never => cmd.global_setting(AppSettings::ColorNever),
            }
        }

        /// Sets the terminal width at which to wrap help messages.
        ///
        /// Using `0` will ignore terminal widths and use source formatting.
        ///
        /// Defaults to current terminal width when `wrap_help` feature flag is enabled.  If the flag
        /// is disabled or it cannot be determined, the default is 100.
        ///
        /// **NOTE:** This setting applies globally and *not* on a per-command basis.
        ///
        /// **NOTE:** This requires the [`wrap_help` feature][crate::_features]
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("myprog")
        ///     .term_width(80)
        /// # ;
        /// ```
        #[inline]
        #[must_use]
        #[cfg(any(not(feature = "unstable-v5"), feature = "wrap_help"))]
        pub fn term_width(mut self, width: usize) -> Self {
            self.term_w = Some(width);
            self
        }

        /// Limit the line length for wrapping help when using the current terminal's width.
        ///
        /// This only applies when [`term_width`][Command::term_width] is unset so that the current
        /// terminal's width will be used.  See [`Command::term_width`] for more details.
        ///
        /// Using `0` will ignore terminal widths and use source formatting (default).
        ///
        /// **NOTE:** This setting applies globally and *not* on a per-command basis.
        ///
        /// **NOTE:** This requires the [`wrap_help` feature][crate::_features]
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("myprog")
        ///     .max_term_width(100)
        /// # ;
        /// ```
        #[inline]
        #[must_use]
        #[cfg(any(not(feature = "unstable-v5"), feature = "wrap_help"))]
        pub fn max_term_width(mut self, w: usize) -> Self {
            self.max_w = Some(w);
            self
        }

        /// Disables `-V` and `--version` flag.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, error::ErrorKind};
        /// let res = Command::new("myprog")
        ///     .disable_version_flag(true)
        ///     .try_get_matches_from(vec![
        ///         "myprog", "-V"
        ///     ]);
        /// assert!(res.is_err());
        /// assert_eq!(res.unwrap_err().kind(), ErrorKind::UnknownArgument);
        /// ```
        #[inline]
        pub fn disable_version_flag(self, yes: bool) -> Self {
            if yes {
                self.global_setting(AppSettings::DisableVersionFlag)
            } else {
                self.unset_global_setting(AppSettings::DisableVersionFlag)
            }
        }

        /// Specifies to use the version of the current command for all [`subcommands`].
        ///
        /// Defaults to `false`; subcommands have independent version strings from their parents.
        ///
        /// **NOTE:** This choice is propagated to all child subcommands.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// Command::new("myprog")
        ///     .version("v1.1")
        ///     .propagate_version(true)
        ///     .subcommand(Command::new("test"))
        ///     .get_matches();
        /// // running `$ myprog test --version` will display
        /// // "myprog-test v1.1"
        /// ```
        ///
        /// [`subcommands`]: crate::Command::subcommand()
        #[inline]
        pub fn propagate_version(self, yes: bool) -> Self {
            if yes {
                self.global_setting(AppSettings::PropagateVersion)
            } else {
                self.unset_global_setting(AppSettings::PropagateVersion)
            }
        }

        /// Places the help string for all arguments and subcommands on the line after them.
        ///
        /// **NOTE:** This choice is propagated to all child subcommands.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// Command::new("myprog")
        ///     .next_line_help(true)
        ///     .get_matches();
        /// ```
        #[inline]
        pub fn next_line_help(self, yes: bool) -> Self {
            if yes {
                self.global_setting(AppSettings::NextLineHelp)
            } else {
                self.unset_global_setting(AppSettings::NextLineHelp)
            }
        }

        /// Disables `-h` and `--help` flag.
        ///
        /// **NOTE:** This choice is propagated to all child subcommands.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, error::ErrorKind};
        /// let res = Command::new("myprog")
        ///     .disable_help_flag(true)
        ///     .try_get_matches_from(vec![
        ///         "myprog", "-h"
        ///     ]);
        /// assert!(res.is_err());
        /// assert_eq!(res.unwrap_err().kind(), ErrorKind::UnknownArgument);
        /// ```
        #[inline]
        pub fn disable_help_flag(self, yes: bool) -> Self {
            if yes {
                self.global_setting(AppSettings::DisableHelpFlag)
            } else {
                self.unset_global_setting(AppSettings::DisableHelpFlag)
            }
        }

        /// Disables the `help` [`subcommand`].
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, error::ErrorKind};
        /// let res = Command::new("myprog")
        ///     .disable_help_subcommand(true)
        ///     // Normally, creating a subcommand causes a `help` subcommand to automatically
        ///     // be generated as well
        ///     .subcommand(Command::new("test"))
        ///     .try_get_matches_from(vec![
        ///         "myprog", "help"
        ///     ]);
        /// assert!(res.is_err());
        /// assert_eq!(res.unwrap_err().kind(), ErrorKind::InvalidSubcommand);
        /// ```
        ///
        /// [`subcommand`]: crate::Command::subcommand()
        #[inline]
        pub fn disable_help_subcommand(self, yes: bool) -> Self {
            if yes {
                self.global_setting(AppSettings::DisableHelpSubcommand)
            } else {
                self.unset_global_setting(AppSettings::DisableHelpSubcommand)
            }
        }

        /// Disables colorized help messages.
        ///
        /// **NOTE:** This choice is propagated to all child subcommands.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("myprog")
        ///     .disable_colored_help(true)
        ///     .get_matches();
        /// ```
        #[inline]
        pub fn disable_colored_help(self, yes: bool) -> Self {
            if yes {
                self.global_setting(AppSettings::DisableColoredHelp)
            } else {
                self.unset_global_setting(AppSettings::DisableColoredHelp)
            }
        }

        /// Panic if help descriptions are omitted.
        ///
        /// **NOTE:** When deriving [`Parser`][crate::Parser], you could instead check this at
        /// compile-time with `#![deny(missing_docs)]`
        ///
        /// **NOTE:** This choice is propagated to all child subcommands.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg};
        /// Command::new("myprog")
        ///     .help_expected(true)
        ///     .arg(
        ///         Arg::new("foo").help("It does foo stuff")
        ///         // As required via `help_expected`, a help message was supplied
        ///      )
        /// #    .get_matches();
        /// ```
        ///
        /// # Panics
        ///
        /// ```rust,no_run
        /// # use clap::{Command, Arg};
        /// Command::new("myapp")
        ///     .help_expected(true)
        ///     .arg(
        ///         Arg::new("foo")
        ///         // Someone forgot to put .about("...") here
        ///         // Since the setting `help_expected` is activated, this will lead to
        ///         // a panic (if you are in debug mode)
        ///     )
        /// #   .get_matches();
        ///```
        #[inline]
        pub fn help_expected(self, yes: bool) -> Self {
            if yes {
                self.global_setting(AppSettings::HelpExpected)
            } else {
                self.unset_global_setting(AppSettings::HelpExpected)
            }
        }

        #[doc(hidden)]
        #[cfg_attr(
            feature = "deprecated",
            deprecated(since = "4.0.0", note = "This is now the default")
        )]
        pub fn dont_collapse_args_in_usage(self, _yes: bool) -> Self {
            self
        }

        /// Tells `clap` *not* to print possible values when displaying help information.
        ///
        /// This can be useful if there are many values, or they are explained elsewhere.
        ///
        /// To set this per argument, see
        /// [`Arg::hide_possible_values`][crate::Arg::hide_possible_values].
        ///
        /// **NOTE:** This choice is propagated to all child subcommands.
        #[inline]
        pub fn hide_possible_values(self, yes: bool) -> Self {
            if yes {
                self.global_setting(AppSettings::HidePossibleValues)
            } else {
                self.unset_global_setting(AppSettings::HidePossibleValues)
            }
        }

        /// Allow partial matches of long arguments or their [aliases].
        ///
        /// For example, to match an argument named `--test`, one could use `--t`, `--te`, `--tes`, and
        /// `--test`.
        ///
        /// **NOTE:** The match *must not* be ambiguous at all in order to succeed. i.e. to match
        /// `--te` to `--test` there could not also be another argument or alias `--temp` because both
        /// start with `--te`
        ///
        /// **NOTE:** This choice is propagated to all child subcommands.
        ///
        /// [aliases]: crate::Command::aliases()
        #[inline]
        pub fn infer_long_args(self, yes: bool) -> Self {
            if yes {
                self.global_setting(AppSettings::InferLongArgs)
            } else {
                self.unset_global_setting(AppSettings::InferLongArgs)
            }
        }

        /// Allow partial matches of [subcommand] names and their [aliases].
        ///
        /// For example, to match a subcommand named `test`, one could use `t`, `te`, `tes`, and
        /// `test`.
        ///
        /// **NOTE:** The match *must not* be ambiguous at all in order to succeed. i.e. to match `te`
        /// to `test` there could not also be a subcommand or alias `temp` because both start with `te`
        ///
        /// **CAUTION:** This setting can interfere with [positional/free arguments], take care when
        /// designing CLIs which allow inferred subcommands and have potential positional/free
        /// arguments whose values could start with the same characters as subcommands. If this is the
        /// case, it's recommended to use settings such as [`Command::args_conflicts_with_subcommands`] in
        /// conjunction with this setting.
        ///
        /// **NOTE:** This choice is propagated to all child subcommands.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// let m = Command::new("prog")
        ///     .infer_subcommands(true)
        ///     .subcommand(Command::new("test"))
        ///     .get_matches_from(vec![
        ///         "prog", "te"
        ///     ]);
        /// assert_eq!(m.subcommand_name(), Some("test"));
        /// ```
        ///
        /// [subcommand]: crate::Command::subcommand()
        /// [positional/free arguments]: crate::Arg::index()
        /// [aliases]: crate::Command::aliases()
        #[inline]
        pub fn infer_subcommands(self, yes: bool) -> Self {
            if yes {
                self.global_setting(AppSettings::InferSubcommands)
            } else {
                self.unset_global_setting(AppSettings::InferSubcommands)
            }
        }
    }

    /// # Command-specific Settings
    ///
    /// These apply only to the current command and are not inherited by subcommands.
    impl Command {
        /// (Re)Sets the program's name.
        ///
        /// See [`Command::new`] for more details.
        ///
        /// # Examples
        ///
        /// ```ignore
        /// let cmd = clap::command!()
        ///     .name("foo");
        ///
        /// // continued logic goes here, such as `cmd.get_matches()` etc.
        /// ```
        #[must_use]
        pub fn name(mut self, name: impl Into<Str>) -> Self {
            self.name = name.into();
            self
        }

        /// Overrides the runtime-determined name of the binary for help and error messages.
        ///
        /// This should only be used when absolutely necessary, such as when the binary name for your
        /// application is misleading, or perhaps *not* how the user should invoke your program.
        ///
        /// **Pro-tip:** When building things such as third party `cargo`
        /// subcommands, this setting **should** be used!
        ///
        /// **NOTE:** This *does not* change or set the name of the binary file on
        /// disk. It only changes what clap thinks the name is for the purposes of
        /// error or help messages.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("My Program")
        ///      .bin_name("my_binary")
        /// # ;
        /// ```
        #[must_use]
        pub fn bin_name(mut self, name: impl IntoResettable<String>) -> Self {
            self.bin_name = name.into_resettable().into_option();
            self
        }

        /// Overrides the runtime-determined display name of the program for help and error messages.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("My Program")
        ///      .display_name("my_program")
        /// # ;
        /// ```
        #[must_use]
        pub fn display_name(mut self, name: impl IntoResettable<String>) -> Self {
            self.display_name = name.into_resettable().into_option();
            self
        }

        /// Sets the author(s) for the help message.
        ///
        /// **Pro-tip:** Use `clap`s convenience macro [`crate_authors!`] to
        /// automatically set your application's author(s) to the same thing as your
        /// crate at compile time.
        ///
        /// **NOTE:** A custom [`help_template`][Command::help_template] is needed for author to show
        /// up.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("myprog")
        ///      .author("Me, me@mymain.com")
        /// # ;
        /// ```
        #[must_use]
        pub fn author(mut self, author: impl IntoResettable<Str>) -> Self {
            self.author = author.into_resettable().into_option();
            self
        }

        /// Sets the program's description for the short help (`-h`).
        ///
        /// If [`Command::long_about`] is not specified, this message will be displayed for `--help`.
        ///
        /// **NOTE:** Only `Command::about` (short format) is used in completion
        /// script generation in order to be concise.
        ///
        /// See also [`crate_description!`](crate::crate_description!).
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("myprog")
        ///     .about("Does really amazing things for great people")
        /// # ;
        /// ```
        #[must_use]
        pub fn about(mut self, about: impl IntoResettable<StyledStr>) -> Self {
            self.about = about.into_resettable().into_option();
            self
        }

        /// Sets the program's description for the long help (`--help`).
        ///
        /// If [`Command::about`] is not specified, this message will be displayed for `-h`.
        ///
        /// **NOTE:** Only [`Command::about`] (short format) is used in completion
        /// script generation in order to be concise.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("myprog")
        ///     .long_about(
        /// "Does really amazing things to great people. Now let's talk a little
        ///  more in depth about how this subcommand really works. It may take about
        ///  a few lines of text, but that's ok!")
        /// # ;
        /// ```
        /// [`Command::about`]: Command::about()
        #[must_use]
        pub fn long_about(mut self, long_about: impl IntoResettable<StyledStr>) -> Self {
            self.long_about = long_about.into_resettable().into_option();
            self
        }

        /// Free-form help text for after auto-generated short help (`-h`).
        ///
        /// This is often used to describe how to use the arguments, caveats to be noted, or license
        /// and contact information.
        ///
        /// If [`Command::after_long_help`] is not specified, this message will be displayed for `--help`.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("myprog")
        ///     .after_help("Does really amazing things for great people... but be careful with -R!")
        /// # ;
        /// ```
        ///
        #[must_use]
        pub fn after_help(mut self, help: impl IntoResettable<StyledStr>) -> Self {
            self.after_help = help.into_resettable().into_option();
            self
        }

        /// Free-form help text for after auto-generated long help (`--help`).
        ///
        /// This is often used to describe how to use the arguments, caveats to be noted, or license
        /// and contact information.
        ///
        /// If [`Command::after_help`] is not specified, this message will be displayed for `-h`.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("myprog")
        ///     .after_long_help("Does really amazing things to great people... but be careful with -R, \
        ///                      like, for real, be careful with this!")
        /// # ;
        /// ```
        #[must_use]
        pub fn after_long_help(mut self, help: impl IntoResettable<StyledStr>) -> Self {
            self.after_long_help = help.into_resettable().into_option();
            self
        }

        /// Free-form help text for before auto-generated short help (`-h`).
        ///
        /// This is often used for header, copyright, or license information.
        ///
        /// If [`Command::before_long_help`] is not specified, this message will be displayed for `--help`.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("myprog")
        ///     .before_help("Some info I'd like to appear before the help info")
        /// # ;
        /// ```
        #[must_use]
        pub fn before_help(mut self, help: impl IntoResettable<StyledStr>) -> Self {
            self.before_help = help.into_resettable().into_option();
            self
        }

        /// Free-form help text for before auto-generated long help (`--help`).
        ///
        /// This is often used for header, copyright, or license information.
        ///
        /// If [`Command::before_help`] is not specified, this message will be displayed for `-h`.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("myprog")
        ///     .before_long_help("Some verbose and long info I'd like to appear before the help info")
        /// # ;
        /// ```
        #[must_use]
        pub fn before_long_help(mut self, help: impl IntoResettable<StyledStr>) -> Self {
            self.before_long_help = help.into_resettable().into_option();
            self
        }

        /// Sets the version for the short version (`-V`) and help messages.
        ///
        /// If [`Command::long_version`] is not specified, this message will be displayed for `--version`.
        ///
        /// **Pro-tip:** Use `clap`s convenience macro [`crate_version!`] to
        /// automatically set your application's version to the same thing as your
        /// crate at compile time.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("myprog")
        ///     .version("v0.1.24")
        /// # ;
        /// ```
        #[must_use]
        pub fn version(mut self, ver: impl IntoResettable<Str>) -> Self {
            self.version = ver.into_resettable().into_option();
            self
        }

        /// Sets the version for the long version (`--version`) and help messages.
        ///
        /// If [`Command::version`] is not specified, this message will be displayed for `-V`.
        ///
        /// **Pro-tip:** Use `clap`s convenience macro [`crate_version!`] to
        /// automatically set your application's version to the same thing as your
        /// crate at compile time.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("myprog")
        ///     .long_version(
        /// "v0.1.24
        ///  commit: abcdef89726d
        ///  revision: 123
        ///  release: 2
        ///  binary: myprog")
        /// # ;
        /// ```
        #[must_use]
        pub fn long_version(mut self, ver: impl IntoResettable<Str>) -> Self {
            self.long_version = ver.into_resettable().into_option();
            self
        }

        /// Overrides the `clap` generated usage string for help and error messages.
        ///
        /// **NOTE:** Using this setting disables `clap`s "context-aware" usage
        /// strings. After this setting is set, this will be *the only* usage string
        /// displayed to the user!
        ///
        /// **NOTE:** Multiple usage lines may be present in the usage argument, but
        /// some rules need to be followed to ensure the usage lines are formatted
        /// correctly by the default help formatter:
        ///
        /// - Do not indent the first usage line.
        /// - Indent all subsequent usage lines with seven spaces.
        /// - The last line must not end with a newline.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// Command::new("myprog")
        ///     .override_usage("myapp [-clDas] <some_file>")
        /// # ;
        /// ```
        ///
        /// Or for multiple usage lines:
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// Command::new("myprog")
        ///     .override_usage(
        ///         "myapp -X [-a] [-b] <file>\n       \
        ///          myapp -Y [-c] <file1> <file2>\n       \
        ///          myapp -Z [-d|-e]"
        ///     )
        /// # ;
        /// ```
        ///
        /// [`ArgMatches::usage`]: ArgMatches::usage()
        #[must_use]
        pub fn override_usage(mut self, usage: impl IntoResettable<StyledStr>) -> Self {
            self.usage_str = usage.into_resettable().into_option();
            self
        }

        /// Overrides the `clap` generated help message (both `-h` and `--help`).
        ///
        /// This should only be used when the auto-generated message does not suffice.
        ///
        /// **NOTE:** This **only** replaces the help message for the current
        /// command, meaning if you are using subcommands, those help messages will
        /// still be auto-generated unless you specify a [`Command::override_help`] for
        /// them as well.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// Command::new("myapp")
        ///     .override_help("myapp v1.0\n\
        ///            Does awesome things\n\
        ///            (C) me@mail.com\n\n\
        ///
        ///            Usage: myapp <opts> <command>\n\n\
        ///
        ///            Options:\n\
        ///            -h, --help       Display this message\n\
        ///            -V, --version    Display version info\n\
        ///            -s <stuff>       Do something with stuff\n\
        ///            -v               Be verbose\n\n\
        ///
        ///            Commands:\n\
        ///            help             Print this message\n\
        ///            work             Do some work")
        /// # ;
        /// ```
        #[must_use]
        pub fn override_help(mut self, help: impl IntoResettable<StyledStr>) -> Self {
            self.help_str = help.into_resettable().into_option();
            self
        }

        /// Sets the help template to be used, overriding the default format.
        ///
        /// **NOTE:** The template system is by design very simple. Therefore, the
        /// tags have to be written in the lowercase and without spacing.
        ///
        /// Tags are given inside curly brackets.
        ///
        /// Valid tags are:
        ///
        ///   * `{name}`                - Display name for the (sub-)command.
        ///   * `{bin}`                 - Binary name.(deprecated)
        ///   * `{version}`             - Version number.
        ///   * `{author}`              - Author information.
        ///   * `{author-with-newline}` - Author followed by `\n`.
        ///   * `{author-section}`      - Author preceded and followed by `\n`.
        ///   * `{about}`               - General description (from [`Command::about`] or
        ///                               [`Command::long_about`]).
        ///   * `{about-with-newline}`  - About followed by `\n`.
        ///   * `{about-section}`       - About preceded and followed by '\n'.
        ///   * `{usage-heading}`       - Automatically generated usage heading.
        ///   * `{usage}`               - Automatically generated or given usage string.
        ///   * `{all-args}`            - Help for all arguments (options, flags, positional
        ///                               arguments, and subcommands) including titles.
        ///   * `{options}`             - Help for options.
        ///   * `{positionals}`         - Help for positional arguments.
        ///   * `{subcommands}`         - Help for subcommands.
        ///   * `{tag}`                 - Standard tab sized used within clap
        ///   * `{after-help}`          - Help from [`Command::after_help`] or [`Command::after_long_help`].
        ///   * `{before-help}`         - Help from [`Command::before_help`] or [`Command::before_long_help`].
        ///
        /// # Examples
        ///
        /// For a very brief help:
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("myprog")
        ///     .version("1.0")
        ///     .help_template("{name} ({version}) - {usage}")
        /// # ;
        /// ```
        ///
        /// For showing more application context:
        ///
        /// ```no_run
        /// # use clap::Command;
        /// Command::new("myprog")
        ///     .version("1.0")
        ///     .help_template("\
        /// {before-help}{name} {version}
        /// {author-with-newline}{about-with-newline}
        /// {usage-heading} {usage}
        ///
        /// {all-args}{after-help}
        /// ")
        /// # ;
        /// ```
        /// [`Command::about`]: Command::about()
        /// [`Command::long_about`]: Command::long_about()
        /// [`Command::after_help`]: Command::after_help()
        /// [`Command::after_long_help`]: Command::after_long_help()
        /// [`Command::before_help`]: Command::before_help()
        /// [`Command::before_long_help`]: Command::before_long_help()
        #[must_use]
        #[cfg(feature = "help")]
        pub fn help_template(mut self, s: impl IntoResettable<StyledStr>) -> Self {
            self.template = s.into_resettable().into_option();
            self
        }

        #[inline]
        #[must_use]
        pub(crate) fn setting<F>(mut self, setting: F) -> Self
        where
            F: Into<AppFlags>,
        {
            self.settings.insert(setting.into());
            self
        }

        #[inline]
        #[must_use]
        pub(crate) fn unset_setting<F>(mut self, setting: F) -> Self
        where
            F: Into<AppFlags>,
        {
            self.settings.remove(setting.into());
            self
        }

        #[inline]
        #[must_use]
        pub(crate) fn global_setting(mut self, setting: AppSettings) -> Self {
            self.settings.set(setting);
            self.g_settings.set(setting);
            self
        }

        #[inline]
        #[must_use]
        pub(crate) fn unset_global_setting(mut self, setting: AppSettings) -> Self {
            self.settings.unset(setting);
            self.g_settings.unset(setting);
            self
        }

        /// Set the default section heading for future args.
        ///
        /// This will be used for any arg that hasn't had [`Arg::help_heading`] called.
        ///
        /// This is useful if the default `Options` or `Arguments` headings are
        /// not specific enough for one's use case.
        ///
        /// For subcommands, see [`Command::subcommand_help_heading`]
        ///
        /// [`Command::arg`]: Command::arg()
        /// [`Arg::help_heading`]: crate::Arg::help_heading()
        #[inline]
        #[must_use]
        pub fn next_help_heading(mut self, heading: impl IntoResettable<Str>) -> Self {
            self.current_help_heading = heading.into_resettable().into_option();
            self
        }

        /// Change the starting value for assigning future display orders for ags.
        ///
        /// This will be used for any arg that hasn't had [`Arg::display_order`] called.
        #[inline]
        #[must_use]
        pub fn next_display_order(mut self, disp_ord: impl IntoResettable<usize>) -> Self {
            self.current_disp_ord = disp_ord.into_resettable().into_option();
            self
        }

        /// Replaces an argument or subcommand used on the CLI at runtime with other arguments or subcommands.
        ///
        /// **Note:** This is gated behind [`unstable-replace`](https://github.com/clap-rs/clap/issues/2836)
        ///
        /// When this method is used, `name` is removed from the CLI, and `target`
        /// is inserted in its place. Parsing continues as if the user typed
        /// `target` instead of `name`.
        ///
        /// This can be used to create "shortcuts" for subcommands, or if a
        /// particular argument has the semantic meaning of several other specific
        /// arguments and values.
        ///
        /// # Examples
        ///
        /// We'll start with the "subcommand short" example. In this example, let's
        /// assume we have a program with a subcommand `module` which can be invoked
        /// via `cmd module`. Now let's also assume `module` also has a subcommand
        /// called `install` which can be invoked `cmd module install`. If for some
        /// reason users needed to be able to reach `cmd module install` via the
        /// short-hand `cmd install`, we'd have several options.
        ///
        /// We *could* create another sibling subcommand to `module` called
        /// `install`, but then we would need to manage another subcommand and manually
        /// dispatch to `cmd module install` handling code. This is error prone and
        /// tedious.
        ///
        /// We could instead use [`Command::replace`] so that, when the user types `cmd
        /// install`, `clap` will replace `install` with `module install` which will
        /// end up getting parsed as if the user typed the entire incantation.
        ///
        /// ```rust
        /// # use clap::Command;
        /// let m = Command::new("cmd")
        ///     .subcommand(Command::new("module")
        ///         .subcommand(Command::new("install")))
        ///     .replace("install", &["module", "install"])
        ///     .get_matches_from(vec!["cmd", "install"]);
        ///
        /// assert!(m.subcommand_matches("module").is_some());
        /// assert!(m.subcommand_matches("module").unwrap().subcommand_matches("install").is_some());
        /// ```
        ///
        /// Now let's show an argument example!
        ///
        /// Let's assume we have an application with two flags `--save-context` and
        /// `--save-runtime`. But often users end up needing to do *both* at the
        /// same time. We can add a third flag `--save-all` which semantically means
        /// the same thing as `cmd --save-context --save-runtime`. To implement that,
        /// we have several options.
        ///
        /// We could create this third argument and manually check if that argument
        /// and in our own consumer code handle the fact that both `--save-context`
        /// and `--save-runtime` *should* have been used. But again this is error
        /// prone and tedious. If we had code relying on checking `--save-context`
        /// and we forgot to update that code to *also* check `--save-all` it'd mean
        /// an error!
        ///
        /// Luckily we can use [`Command::replace`] so that when the user types
        /// `--save-all`, `clap` will replace that argument with `--save-context
        /// --save-runtime`, and parsing will continue like normal. Now all our code
        /// that was originally checking for things like `--save-context` doesn't
        /// need to change!
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgAction};
        /// let m = Command::new("cmd")
        ///     .arg(Arg::new("save-context")
        ///         .long("save-context")
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("save-runtime")
        ///         .long("save-runtime")
        ///         .action(ArgAction::SetTrue))
        ///     .replace("--save-all", &["--save-context", "--save-runtime"])
        ///     .get_matches_from(vec!["cmd", "--save-all"]);
        ///
        /// assert!(*m.get_one::<bool>("save-context").expect("defaulted by clap"));
        /// assert!(*m.get_one::<bool>("save-runtime").expect("defaulted by clap"));
        /// ```
        ///
        /// This can also be used with options, for example if our application with
        /// `--save-*` above also had a `--format=TYPE` option. Let's say it
        /// accepted `txt` or `json` values. However, when `--save-all` is used,
        /// only `--format=json` is allowed, or valid. We could change the example
        /// above to enforce this:
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgAction};
        /// let m = Command::new("cmd")
        ///     .arg(Arg::new("save-context")
        ///         .long("save-context")
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("save-runtime")
        ///         .long("save-runtime")
        ///         .action(ArgAction::SetTrue))
        ///     .arg(Arg::new("format")
        ///         .long("format")
        ///         .action(ArgAction::Set)
        ///         .value_parser(["txt", "json"]))
        ///     .replace("--save-all", &["--save-context", "--save-runtime", "--format=json"])
        ///     .get_matches_from(vec!["cmd", "--save-all"]);
        ///
        /// assert!(*m.get_one::<bool>("save-context").expect("defaulted by clap"));
        /// assert!(*m.get_one::<bool>("save-runtime").expect("defaulted by clap"));
        /// assert_eq!(m.get_one::<String>("format").unwrap(), "json");
        /// ```
        ///
        /// [`Command::replace`]: Command::replace()
        #[inline]
        #[cfg(feature = "unstable-replace")]
        #[must_use]
        pub fn replace(
            mut self,
            name: impl Into<Str>,
            target: impl IntoIterator<Item = impl Into<Str>>,
        ) -> Self {
            self.replacers
                .insert(name.into(), target.into_iter().map(Into::into).collect());
            self
        }

        /// Exit gracefully if no arguments are present (e.g. `$ myprog`).
        ///
        /// **NOTE:** [`subcommands`] count as arguments
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command};
        /// Command::new("myprog")
        ///     .arg_required_else_help(true);
        /// ```
        ///
        /// [`subcommands`]: crate::Command::subcommand()
        /// [`Arg::default_value`]: crate::Arg::default_value()
        #[inline]
        pub fn arg_required_else_help(self, yes: bool) -> Self {
            if yes {
                self.setting(AppSettings::ArgRequiredElseHelp)
            } else {
                self.unset_setting(AppSettings::ArgRequiredElseHelp)
            }
        }

        #[doc(hidden)]
        #[cfg_attr(
            feature = "deprecated",
            deprecated(since = "4.0.0", note = "Replaced with `Arg::allow_hyphen_values`")
        )]
        pub fn allow_hyphen_values(self, yes: bool) -> Self {
            if yes {
                self.setting(AppSettings::AllowHyphenValues)
            } else {
                self.unset_setting(AppSettings::AllowHyphenValues)
            }
        }

        #[doc(hidden)]
        #[cfg_attr(
            feature = "deprecated",
            deprecated(since = "4.0.0", note = "Replaced with `Arg::allow_negative_numbers`")
        )]
        pub fn allow_negative_numbers(self, yes: bool) -> Self {
            if yes {
                self.setting(AppSettings::AllowNegativeNumbers)
            } else {
                self.unset_setting(AppSettings::AllowNegativeNumbers)
            }
        }

        #[doc(hidden)]
        #[cfg_attr(
            feature = "deprecated",
            deprecated(since = "4.0.0", note = "Replaced with `Arg::trailing_var_arg`")
        )]
        pub fn trailing_var_arg(self, yes: bool) -> Self {
            if yes {
                self.setting(AppSettings::TrailingVarArg)
            } else {
                self.unset_setting(AppSettings::TrailingVarArg)
            }
        }

        /// Allows one to implement two styles of CLIs where positionals can be used out of order.
        ///
        /// The first example is a CLI where the second to last positional argument is optional, but
        /// the final positional argument is required. Such as `$ prog [optional] <required>` where one
        /// of the two following usages is allowed:
        ///
        /// * `$ prog [optional] <required>`
        /// * `$ prog <required>`
        ///
        /// This would otherwise not be allowed. This is useful when `[optional]` has a default value.
        ///
        /// **Note:** when using this style of "missing positionals" the final positional *must* be
        /// [required] if `--` will not be used to skip to the final positional argument.
        ///
        /// **Note:** This style also only allows a single positional argument to be "skipped" without
        /// the use of `--`. To skip more than one, see the second example.
        ///
        /// The second example is when one wants to skip multiple optional positional arguments, and use
        /// of the `--` operator is OK (but not required if all arguments will be specified anyways).
        ///
        /// For example, imagine a CLI which has three positional arguments `[foo] [bar] [baz]...` where
        /// `baz` accepts multiple values (similar to man `ARGS...` style training arguments).
        ///
        /// With this setting the following invocations are posisble:
        ///
        /// * `$ prog foo bar baz1 baz2 baz3`
        /// * `$ prog foo -- baz1 baz2 baz3`
        /// * `$ prog -- baz1 baz2 baz3`
        ///
        /// # Examples
        ///
        /// Style number one from above:
        ///
        /// ```rust
        /// # use clap::{Command, Arg};
        /// // Assume there is an external subcommand named "subcmd"
        /// let m = Command::new("myprog")
        ///     .allow_missing_positional(true)
        ///     .arg(Arg::new("arg1"))
        ///     .arg(Arg::new("arg2")
        ///         .required(true))
        ///     .get_matches_from(vec![
        ///         "prog", "other"
        ///     ]);
        ///
        /// assert_eq!(m.get_one::<String>("arg1"), None);
        /// assert_eq!(m.get_one::<String>("arg2").unwrap(), "other");
        /// ```
        ///
        /// Now the same example, but using a default value for the first optional positional argument
        ///
        /// ```rust
        /// # use clap::{Command, Arg};
        /// // Assume there is an external subcommand named "subcmd"
        /// let m = Command::new("myprog")
        ///     .allow_missing_positional(true)
        ///     .arg(Arg::new("arg1")
        ///         .default_value("something"))
        ///     .arg(Arg::new("arg2")
        ///         .required(true))
        ///     .get_matches_from(vec![
        ///         "prog", "other"
        ///     ]);
        ///
        /// assert_eq!(m.get_one::<String>("arg1").unwrap(), "something");
        /// assert_eq!(m.get_one::<String>("arg2").unwrap(), "other");
        /// ```
        ///
        /// Style number two from above:
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgAction};
        /// // Assume there is an external subcommand named "subcmd"
        /// let m = Command::new("myprog")
        ///     .allow_missing_positional(true)
        ///     .arg(Arg::new("foo"))
        ///     .arg(Arg::new("bar"))
        ///     .arg(Arg::new("baz").action(ArgAction::Set).num_args(1..))
        ///     .get_matches_from(vec![
        ///         "prog", "foo", "bar", "baz1", "baz2", "baz3"
        ///     ]);
        ///
        /// assert_eq!(m.get_one::<String>("foo").unwrap(), "foo");
        /// assert_eq!(m.get_one::<String>("bar").unwrap(), "bar");
        /// assert_eq!(m.get_many::<String>("baz").unwrap().collect::<Vec<_>>(), &["baz1", "baz2", "baz3"]);
        /// ```
        ///
        /// Now nofice if we don't specify `foo` or `baz` but use the `--` operator.
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgAction};
        /// // Assume there is an external subcommand named "subcmd"
        /// let m = Command::new("myprog")
        ///     .allow_missing_positional(true)
        ///     .arg(Arg::new("foo"))
        ///     .arg(Arg::new("bar"))
        ///     .arg(Arg::new("baz").action(ArgAction::Set).num_args(1..))
        ///     .get_matches_from(vec![
        ///         "prog", "--", "baz1", "baz2", "baz3"
        ///     ]);
        ///
        /// assert_eq!(m.get_one::<String>("foo"), None);
        /// assert_eq!(m.get_one::<String>("bar"), None);
        /// assert_eq!(m.get_many::<String>("baz").unwrap().collect::<Vec<_>>(), &["baz1", "baz2", "baz3"]);
        /// ```
        ///
        /// [required]: crate::Arg::required()
        #[inline]
        pub fn allow_missing_positional(self, yes: bool) -> Self {
            if yes {
                self.setting(AppSettings::AllowMissingPositional)
            } else {
                self.unset_setting(AppSettings::AllowMissingPositional)
            }
        }
    }

    /// # Subcommand-specific Settings
    impl Command {
        /// Sets the short version of the subcommand flag without the preceding `-`.
        ///
        /// Allows the subcommand to be used as if it were an [`Arg::short`].
        ///
        /// # Examples
        ///
        /// ```
        /// # use clap::{Command, Arg, ArgAction};
        /// let matches = Command::new("pacman")
        ///     .subcommand(
        ///         Command::new("sync").short_flag('S').arg(
        ///             Arg::new("search")
        ///                 .short('s')
        ///                 .long("search")
        ///                 .action(ArgAction::SetTrue)
        ///                 .help("search remote repositories for matching strings"),
        ///         ),
        ///     )
        ///     .get_matches_from(vec!["pacman", "-Ss"]);
        ///
        /// assert_eq!(matches.subcommand_name().unwrap(), "sync");
        /// let sync_matches = matches.subcommand_matches("sync").unwrap();
        /// assert!(*sync_matches.get_one::<bool>("search").expect("defaulted by clap"));
        /// ```
        /// [`Arg::short`]: Arg::short()
        #[must_use]
        pub fn short_flag(mut self, short: impl IntoResettable<char>) -> Self {
            self.short_flag = short.into_resettable().into_option();
            self
        }

        /// Sets the long version of the subcommand flag without the preceding `--`.
        ///
        /// Allows the subcommand to be used as if it were an [`Arg::long`].
        ///
        /// **NOTE:** Any leading `-` characters will be stripped.
        ///
        /// # Examples
        ///
        /// To set `long_flag` use a word containing valid UTF-8 codepoints. If you supply a double leading
        /// `--` such as `--sync` they will be stripped. Hyphens in the middle of the word; however,
        /// will *not* be stripped (i.e. `sync-file` is allowed).
        ///
        /// ```
        /// # use clap::{Command, Arg, ArgAction};
        /// let matches = Command::new("pacman")
        ///     .subcommand(
        ///         Command::new("sync").long_flag("sync").arg(
        ///             Arg::new("search")
        ///                 .short('s')
        ///                 .long("search")
        ///                 .action(ArgAction::SetTrue)
        ///                 .help("search remote repositories for matching strings"),
        ///         ),
        ///     )
        ///     .get_matches_from(vec!["pacman", "--sync", "--search"]);
        ///
        /// assert_eq!(matches.subcommand_name().unwrap(), "sync");
        /// let sync_matches = matches.subcommand_matches("sync").unwrap();
        /// assert!(*sync_matches.get_one::<bool>("search").expect("defaulted by clap"));
        /// ```
        ///
        /// [`Arg::long`]: Arg::long()
        #[must_use]
        pub fn long_flag(mut self, long: impl Into<Str>) -> Self {
            self.long_flag = Some(long.into());
            self
        }

        /// Sets a hidden alias to this subcommand.
        ///
        /// This allows the subcommand to be accessed via *either* the original name, or this given
        /// alias. This is more efficient and easier than creating multiple hidden subcommands as one
        /// only needs to check for the existence of this command, and not all aliased variants.
        ///
        /// **NOTE:** Aliases defined with this method are *hidden* from the help
        /// message. If you're looking for aliases that will be displayed in the help
        /// message, see [`Command::visible_alias`].
        ///
        /// **NOTE:** When using aliases and checking for the existence of a
        /// particular subcommand within an [`ArgMatches`] struct, one only needs to
        /// search for the original name and not all aliases.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg, };
        /// let m = Command::new("myprog")
        ///     .subcommand(Command::new("test")
        ///         .alias("do-stuff"))
        ///     .get_matches_from(vec!["myprog", "do-stuff"]);
        /// assert_eq!(m.subcommand_name(), Some("test"));
        /// ```
        /// [`Command::visible_alias`]: Command::visible_alias()
        #[must_use]
        pub fn alias(mut self, name: impl IntoResettable<Str>) -> Self {
            if let Some(name) = name.into_resettable().into_option() {
                self.aliases.push((name, false));
            } else {
                self.aliases.clear();
            }
            self
        }

        /// Add an alias, which functions as  "hidden" short flag subcommand
        ///
        /// This will automatically dispatch as if this subcommand was used. This is more efficient,
        /// and easier than creating multiple hidden subcommands as one only needs to check for the
        /// existence of this command, and not all variants.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg, };
        /// let m = Command::new("myprog")
        ///             .subcommand(Command::new("test").short_flag('t')
        ///                 .short_flag_alias('d'))
        ///             .get_matches_from(vec!["myprog", "-d"]);
        /// assert_eq!(m.subcommand_name(), Some("test"));
        /// ```
        #[must_use]
        pub fn short_flag_alias(mut self, name: impl IntoResettable<char>) -> Self {
            if let Some(name) = name.into_resettable().into_option() {
                debug_assert!(name != '-', "short alias name cannot be `-`");
                self.short_flag_aliases.push((name, false));
            } else {
                self.short_flag_aliases.clear();
            }
            self
        }

        /// Add an alias, which functions as a "hidden" long flag subcommand.
        ///
        /// This will automatically dispatch as if this subcommand was used. This is more efficient,
        /// and easier than creating multiple hidden subcommands as one only needs to check for the
        /// existence of this command, and not all variants.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg, };
        /// let m = Command::new("myprog")
        ///             .subcommand(Command::new("test").long_flag("test")
        ///                 .long_flag_alias("testing"))
        ///             .get_matches_from(vec!["myprog", "--testing"]);
        /// assert_eq!(m.subcommand_name(), Some("test"));
        /// ```
        #[must_use]
        pub fn long_flag_alias(mut self, name: impl IntoResettable<Str>) -> Self {
            if let Some(name) = name.into_resettable().into_option() {
                self.long_flag_aliases.push((name, false));
            } else {
                self.long_flag_aliases.clear();
            }
            self
        }

        /// Sets multiple hidden aliases to this subcommand.
        ///
        /// This allows the subcommand to be accessed via *either* the original name or any of the
        /// given aliases. This is more efficient, and easier than creating multiple hidden subcommands
        /// as one only needs to check for the existence of this command and not all aliased variants.
        ///
        /// **NOTE:** Aliases defined with this method are *hidden* from the help
        /// message. If looking for aliases that will be displayed in the help
        /// message, see [`Command::visible_aliases`].
        ///
        /// **NOTE:** When using aliases and checking for the existence of a
        /// particular subcommand within an [`ArgMatches`] struct, one only needs to
        /// search for the original name and not all aliases.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg};
        /// let m = Command::new("myprog")
        ///     .subcommand(Command::new("test")
        ///         .aliases(["do-stuff", "do-tests", "tests"]))
        ///         .arg(Arg::new("input")
        ///             .help("the file to add")
        ///             .required(false))
        ///     .get_matches_from(vec!["myprog", "do-tests"]);
        /// assert_eq!(m.subcommand_name(), Some("test"));
        /// ```
        /// [`Command::visible_aliases`]: Command::visible_aliases()
        #[must_use]
        pub fn aliases(mut self, names: impl IntoIterator<Item = impl Into<Str>>) -> Self {
            self.aliases
                .extend(names.into_iter().map(|n| (n.into(), false)));
            self
        }

        /// Add aliases, which function as "hidden" short flag subcommands.
        ///
        /// These will automatically dispatch as if this subcommand was used. This is more efficient,
        /// and easier than creating multiple hidden subcommands as one only needs to check for the
        /// existence of this command, and not all variants.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg, };
        /// let m = Command::new("myprog")
        ///     .subcommand(Command::new("test").short_flag('t')
        ///         .short_flag_aliases(['a', 'b', 'c']))
        ///         .arg(Arg::new("input")
        ///             .help("the file to add")
        ///             .required(false))
        ///     .get_matches_from(vec!["myprog", "-a"]);
        /// assert_eq!(m.subcommand_name(), Some("test"));
        /// ```
        #[must_use]
        pub fn short_flag_aliases(mut self, names: impl IntoIterator<Item = char>) -> Self {
            for s in names {
                debug_assert!(s != '-', "short alias name cannot be `-`");
                self.short_flag_aliases.push((s, false));
            }
            self
        }

        /// Add aliases, which function as "hidden" long flag subcommands.
        ///
        /// These will automatically dispatch as if this subcommand was used. This is more efficient,
        /// and easier than creating multiple hidden subcommands as one only needs to check for the
        /// existence of this command, and not all variants.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg, };
        /// let m = Command::new("myprog")
        ///             .subcommand(Command::new("test").long_flag("test")
        ///                 .long_flag_aliases(["testing", "testall", "test_all"]))
        ///                 .arg(Arg::new("input")
        ///                             .help("the file to add")
        ///                             .required(false))
        ///             .get_matches_from(vec!["myprog", "--testing"]);
        /// assert_eq!(m.subcommand_name(), Some("test"));
        /// ```
        #[must_use]
        pub fn long_flag_aliases(mut self, names: impl IntoIterator<Item = impl Into<Str>>) -> Self {
            for s in names {
                self = self.long_flag_alias(s)
            }
            self
        }

        /// Sets a visible alias to this subcommand.
        ///
        /// This allows the subcommand to be accessed via *either* the
        /// original name or the given alias. This is more efficient and easier
        /// than creating hidden subcommands as one only needs to check for
        /// the existence of this command and not all aliased variants.
        ///
        /// **NOTE:** The alias defined with this method is *visible* from the help
        /// message and displayed as if it were just another regular subcommand. If
        /// looking for an alias that will not be displayed in the help message, see
        /// [`Command::alias`].
        ///
        /// **NOTE:** When using aliases and checking for the existence of a
        /// particular subcommand within an [`ArgMatches`] struct, one only needs to
        /// search for the original name and not all aliases.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// let m = Command::new("myprog")
        ///     .subcommand(Command::new("test")
        ///         .visible_alias("do-stuff"))
        ///     .get_matches_from(vec!["myprog", "do-stuff"]);
        /// assert_eq!(m.subcommand_name(), Some("test"));
        /// ```
        /// [`Command::alias`]: Command::alias()
        #[must_use]
        pub fn visible_alias(mut self, name: impl IntoResettable<Str>) -> Self {
            if let Some(name) = name.into_resettable().into_option() {
                self.aliases.push((name, true));
            } else {
                self.aliases.clear();
            }
            self
        }

        /// Add an alias, which functions as  "visible" short flag subcommand
        ///
        /// This will automatically dispatch as if this subcommand was used. This is more efficient,
        /// and easier than creating multiple hidden subcommands as one only needs to check for the
        /// existence of this command, and not all variants.
        ///
        /// See also [`Command::short_flag_alias`].
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg, };
        /// let m = Command::new("myprog")
        ///             .subcommand(Command::new("test").short_flag('t')
        ///                 .visible_short_flag_alias('d'))
        ///             .get_matches_from(vec!["myprog", "-d"]);
        /// assert_eq!(m.subcommand_name(), Some("test"));
        /// ```
        /// [`Command::short_flag_alias`]: Command::short_flag_alias()
        #[must_use]
        pub fn visible_short_flag_alias(mut self, name: impl IntoResettable<char>) -> Self {
            if let Some(name) = name.into_resettable().into_option() {
                debug_assert!(name != '-', "short alias name cannot be `-`");
                self.short_flag_aliases.push((name, true));
            } else {
                self.short_flag_aliases.clear();
            }
            self
        }

        /// Add an alias, which functions as a "visible" long flag subcommand.
        ///
        /// This will automatically dispatch as if this subcommand was used. This is more efficient,
        /// and easier than creating multiple hidden subcommands as one only needs to check for the
        /// existence of this command, and not all variants.
        ///
        /// See also [`Command::long_flag_alias`].
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg, };
        /// let m = Command::new("myprog")
        ///             .subcommand(Command::new("test").long_flag("test")
        ///                 .visible_long_flag_alias("testing"))
        ///             .get_matches_from(vec!["myprog", "--testing"]);
        /// assert_eq!(m.subcommand_name(), Some("test"));
        /// ```
        /// [`Command::long_flag_alias`]: Command::long_flag_alias()
        #[must_use]
        pub fn visible_long_flag_alias(mut self, name: impl IntoResettable<Str>) -> Self {
            if let Some(name) = name.into_resettable().into_option() {
                self.long_flag_aliases.push((name, true));
            } else {
                self.long_flag_aliases.clear();
            }
            self
        }

        /// Sets multiple visible aliases to this subcommand.
        ///
        /// This allows the subcommand to be accessed via *either* the
        /// original name or any of the given aliases. This is more efficient and easier
        /// than creating multiple hidden subcommands as one only needs to check for
        /// the existence of this command and not all aliased variants.
        ///
        /// **NOTE:** The alias defined with this method is *visible* from the help
        /// message and displayed as if it were just another regular subcommand. If
        /// looking for an alias that will not be displayed in the help message, see
        /// [`Command::alias`].
        ///
        /// **NOTE:** When using aliases, and checking for the existence of a
        /// particular subcommand within an [`ArgMatches`] struct, one only needs to
        /// search for the original name and not all aliases.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg, };
        /// let m = Command::new("myprog")
        ///     .subcommand(Command::new("test")
        ///         .visible_aliases(["do-stuff", "tests"]))
        ///     .get_matches_from(vec!["myprog", "do-stuff"]);
        /// assert_eq!(m.subcommand_name(), Some("test"));
        /// ```
        /// [`Command::alias`]: Command::alias()
        #[must_use]
        pub fn visible_aliases(mut self, names: impl IntoIterator<Item = impl Into<Str>>) -> Self {
            self.aliases
                .extend(names.into_iter().map(|n| (n.into(), true)));
            self
        }

        /// Add aliases, which function as *visible* short flag subcommands.
        ///
        /// See [`Command::short_flag_aliases`].
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg, };
        /// let m = Command::new("myprog")
        ///             .subcommand(Command::new("test").short_flag('b')
        ///                 .visible_short_flag_aliases(['t']))
        ///             .get_matches_from(vec!["myprog", "-t"]);
        /// assert_eq!(m.subcommand_name(), Some("test"));
        /// ```
        /// [`Command::short_flag_aliases`]: Command::short_flag_aliases()
        #[must_use]
        pub fn visible_short_flag_aliases(mut self, names: impl IntoIterator<Item = char>) -> Self {
            for s in names {
                debug_assert!(s != '-', "short alias name cannot be `-`");
                self.short_flag_aliases.push((s, true));
            }
            self
        }

        /// Add aliases, which function as *visible* long flag subcommands.
        ///
        /// See [`Command::long_flag_aliases`].
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg, };
        /// let m = Command::new("myprog")
        ///             .subcommand(Command::new("test").long_flag("test")
        ///                 .visible_long_flag_aliases(["testing", "testall", "test_all"]))
        ///             .get_matches_from(vec!["myprog", "--testing"]);
        /// assert_eq!(m.subcommand_name(), Some("test"));
        /// ```
        /// [`Command::long_flag_aliases`]: Command::long_flag_aliases()
        #[must_use]
        pub fn visible_long_flag_aliases(
            mut self,
            names: impl IntoIterator<Item = impl Into<Str>>,
        ) -> Self {
            for s in names {
                self = self.visible_long_flag_alias(s);
            }
            self
        }

        /// Set the placement of this subcommand within the help.
        ///
        /// Subcommands with a lower value will be displayed first in the help message.  Subcommands
        /// with duplicate display orders will be displayed in alphabetical order.
        ///
        /// This is helpful when one would like to emphasize frequently used subcommands, or prioritize
        /// those towards the top of the list.
        ///
        /// **NOTE:** The default is 999 for all subcommands.
        ///
        /// # Examples
        ///
        #[cfg_attr(not(feature = "help"), doc = " ```ignore")]
        #[cfg_attr(feature = "help", doc = " ```")]
        /// # use clap::{Command, };
        /// let m = Command::new("cust-ord")
        ///     .subcommand(Command::new("alpha") // typically subcommands are grouped
        ///                                                // alphabetically by name. Subcommands
        ///                                                // without a display_order have a value of
        ///                                                // 999 and are displayed alphabetically with
        ///                                                // all other 999 subcommands
        ///         .about("Some help and text"))
        ///     .subcommand(Command::new("beta")
        ///         .display_order(1)   // In order to force this subcommand to appear *first*
        ///                             // all we have to do is give it a value lower than 999.
        ///                             // Any other subcommands with a value of 1 will be displayed
        ///                             // alphabetically with this one...then 2 values, then 3, etc.
        ///         .about("I should be first!"))
        ///     .get_matches_from(vec![
        ///         "cust-ord", "--help"
        ///     ]);
        /// ```
        ///
        /// The above example displays the following help message
        ///
        /// ```text
        /// cust-ord
        ///
        /// Usage: cust-ord [OPTIONS]
        ///
        /// Commands:
        ///     beta    I should be first!
        ///     alpha   Some help and text
        ///
        /// Options:
        ///     -h, --help       Print help information
        ///     -V, --version    Print version information
        /// ```
        #[inline]
        #[must_use]
        pub fn display_order(mut self, ord: impl IntoResettable<usize>) -> Self {
            self.disp_ord = ord.into_resettable().into_option();
            self
        }

        /// Specifies that this [`subcommand`] should be hidden from help messages
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg};
        /// Command::new("myprog")
        ///     .subcommand(
        ///         Command::new("test").hide(true)
        ///     )
        /// # ;
        /// ```
        ///
        /// [`subcommand`]: crate::Command::subcommand()
        #[inline]
        pub fn hide(self, yes: bool) -> Self {
            if yes {
                self.setting(AppSettings::Hidden)
            } else {
                self.unset_setting(AppSettings::Hidden)
            }
        }

        /// If no [`subcommand`] is present at runtime, error and exit gracefully.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, error::ErrorKind};
        /// let err = Command::new("myprog")
        ///     .subcommand_required(true)
        ///     .subcommand(Command::new("test"))
        ///     .try_get_matches_from(vec![
        ///         "myprog",
        ///     ]);
        /// assert!(err.is_err());
        /// assert_eq!(err.unwrap_err().kind(), ErrorKind::MissingSubcommand);
        /// # ;
        /// ```
        ///
        /// [`subcommand`]: crate::Command::subcommand()
        pub fn subcommand_required(self, yes: bool) -> Self {
            if yes {
                self.setting(AppSettings::SubcommandRequired)
            } else {
                self.unset_setting(AppSettings::SubcommandRequired)
            }
        }

        /// Assume unexpected positional arguments are a [`subcommand`].
        ///
        /// Arguments will be stored in the `""` argument in the [`ArgMatches`]
        ///
        /// **NOTE:** Use this setting with caution,
        /// as a truly unexpected argument (i.e. one that is *NOT* an external subcommand)
        /// will **not** cause an error and instead be treated as a potential subcommand.
        /// One should check for such cases manually and inform the user appropriately.
        ///
        /// **NOTE:** A built-in subcommand will be parsed as an external subcommand when escaped with
        /// `--`.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use std::ffi::OsString;
        /// # use clap::Command;
        /// // Assume there is an external subcommand named "subcmd"
        /// let m = Command::new("myprog")
        ///     .allow_external_subcommands(true)
        ///     .get_matches_from(vec![
        ///         "myprog", "subcmd", "--option", "value", "-fff", "--flag"
        ///     ]);
        ///
        /// // All trailing arguments will be stored under the subcommand's sub-matches using an empty
        /// // string argument name
        /// match m.subcommand() {
        ///     Some((external, ext_m)) => {
        ///          let ext_args: Vec<_> = ext_m.get_many::<OsString>("").unwrap().collect();
        ///          assert_eq!(external, "subcmd");
        ///          assert_eq!(ext_args, ["--option", "value", "-fff", "--flag"]);
        ///     },
        ///     _ => {},
        /// }
        /// ```
        ///
        /// [`subcommand`]: crate::Command::subcommand()
        /// [`ArgMatches`]: crate::ArgMatches
        /// [`ErrorKind::UnknownArgument`]: crate::error::ErrorKind::UnknownArgument
        pub fn allow_external_subcommands(self, yes: bool) -> Self {
            if yes {
                self.setting(AppSettings::AllowExternalSubcommands)
            } else {
                self.unset_setting(AppSettings::AllowExternalSubcommands)
            }
        }

        /// Specifies how to parse external subcommand arguments.
        ///
        /// The default parser is for `OsString`.  This can be used to switch it to `String` or another
        /// type.
        ///
        /// **NOTE:** Setting this requires [`Command::allow_external_subcommands`]
        ///
        /// # Examples
        ///
        #[cfg_attr(not(unix), doc = " ```ignore")]
        #[cfg_attr(unix, doc = " ```")]
        /// # use std::ffi::OsString;
        /// # use clap::Command;
        /// # use clap::value_parser;
        /// // Assume there is an external subcommand named "subcmd"
        /// let m = Command::new("myprog")
        ///     .allow_external_subcommands(true)
        ///     .get_matches_from(vec![
        ///         "myprog", "subcmd", "--option", "value", "-fff", "--flag"
        ///     ]);
        ///
        /// // All trailing arguments will be stored under the subcommand's sub-matches using an empty
        /// // string argument name
        /// match m.subcommand() {
        ///     Some((external, ext_m)) => {
        ///          let ext_args: Vec<_> = ext_m.get_many::<OsString>("").unwrap().collect();
        ///          assert_eq!(external, "subcmd");
        ///          assert_eq!(ext_args, ["--option", "value", "-fff", "--flag"]);
        ///     },
        ///     _ => {},
        /// }
        /// ```
        ///
        /// ```
        /// # use clap::Command;
        /// # use clap::value_parser;
        /// // Assume there is an external subcommand named "subcmd"
        /// let m = Command::new("myprog")
        ///     .external_subcommand_value_parser(value_parser!(String))
        ///     .get_matches_from(vec![
        ///         "myprog", "subcmd", "--option", "value", "-fff", "--flag"
        ///     ]);
        ///
        /// // All trailing arguments will be stored under the subcommand's sub-matches using an empty
        /// // string argument name
        /// match m.subcommand() {
        ///     Some((external, ext_m)) => {
        ///          let ext_args: Vec<_> = ext_m.get_many::<String>("").unwrap().collect();
        ///          assert_eq!(external, "subcmd");
        ///          assert_eq!(ext_args, ["--option", "value", "-fff", "--flag"]);
        ///     },
        ///     _ => {},
        /// }
        /// ```
        ///
        /// [`subcommands`]: crate::Command::subcommand()
        pub fn external_subcommand_value_parser(
            mut self,
            parser: impl IntoResettable<super::ValueParser>,
        ) -> Self {
            self.external_value_parser = parser.into_resettable().into_option();
            self
        }

        /// Specifies that use of an argument prevents the use of [`subcommands`].
        ///
        /// By default `clap` allows arguments between subcommands such
        /// as `<cmd> [cmd_args] <subcmd> [subcmd_args] <subsubcmd> [subsubcmd_args]`.
        ///
        /// This setting disables that functionality and says that arguments can
        /// only follow the *final* subcommand. For instance using this setting
        /// makes only the following invocations possible:
        ///
        /// * `<cmd> <subcmd> <subsubcmd> [subsubcmd_args]`
        /// * `<cmd> <subcmd> [subcmd_args]`
        /// * `<cmd> [cmd_args]`
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::Command;
        /// Command::new("myprog")
        ///     .args_conflicts_with_subcommands(true);
        /// ```
        ///
        /// [`subcommands`]: crate::Command::subcommand()
        pub fn args_conflicts_with_subcommands(self, yes: bool) -> Self {
            if yes {
                self.setting(AppSettings::ArgsNegateSubcommands)
            } else {
                self.unset_setting(AppSettings::ArgsNegateSubcommands)
            }
        }

        /// Prevent subcommands from being consumed as an arguments value.
        ///
        /// By default, if an option taking multiple values is followed by a subcommand, the
        /// subcommand will be parsed as another value.
        ///
        /// ```text
        /// cmd --foo val1 val2 subcommand
        ///           --------- ----------
        ///             values   another value
        /// ```
        ///
        /// This setting instructs the parser to stop when encountering a subcommand instead of
        /// greedily consuming arguments.
        ///
        /// ```text
        /// cmd --foo val1 val2 subcommand
        ///           --------- ----------
        ///             values   subcommand
        /// ```
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Command, Arg, ArgAction};
        /// let cmd = Command::new("cmd").subcommand(Command::new("sub")).arg(
        ///     Arg::new("arg")
        ///         .long("arg")
        ///         .num_args(1..)
        ///         .action(ArgAction::Set),
        /// );
        ///
        /// let matches = cmd
        ///     .clone()
        ///     .try_get_matches_from(&["cmd", "--arg", "1", "2", "3", "sub"])
        ///     .unwrap();
        /// assert_eq!(
        ///     matches.get_many::<String>("arg").unwrap().collect::<Vec<_>>(),
        ///     &["1", "2", "3", "sub"]
        /// );
        /// assert!(matches.subcommand_matches("sub").is_none());
        ///
        /// let matches = cmd
        ///     .subcommand_precedence_over_arg(true)
        ///     .try_get_matches_from(&["cmd", "--arg", "1", "2", "3", "sub"])
        ///     .unwrap();
        /// assert_eq!(
        ///     matches.get_many::<String>("arg").unwrap().collect::<Vec<_>>(),
        ///     &["1", "2", "3"]
        /// );
        /// assert!(matches.subcommand_matches("sub").is_some());
        /// ```
        pub fn subcommand_precedence_over_arg(self, yes: bool) -> Self {
            if yes {
                self.setting(AppSettings::SubcommandPrecedenceOverArg)
            } else {
                self.unset_setting(AppSettings::SubcommandPrecedenceOverArg)
            }
        }

        /// Allows [`subcommands`] to override all requirements of the parent command.
        ///
        /// For example, if you had a subcommand or top level application with a required argument
        /// that is only required as long as there is no subcommand present,
        /// using this setting would allow you to set those arguments to [`Arg::required(true)`]
        /// and yet receive no error so long as the user uses a valid subcommand instead.
        ///
        /// **NOTE:** This defaults to false (using subcommand does *not* negate requirements)
        ///
        /// # Examples
        ///
        /// This first example shows that it is an error to not use a required argument
        ///
        /// ```rust
        /// # use clap::{Command, Arg, error::ErrorKind};
        /// let err = Command::new("myprog")
        ///     .subcommand_negates_reqs(true)
        ///     .arg(Arg::new("opt").required(true))
        ///     .subcommand(Command::new("test"))
        ///     .try_get_matches_from(vec![
        ///         "myprog"
        ///     ]);
        /// assert!(err.is_err());
        /// assert_eq!(err.unwrap_err().kind(), ErrorKind::MissingRequiredArgument);
        /// # ;
        /// ```
        ///
        /// This next example shows that it is no longer error to not use a required argument if a
        /// valid subcommand is used.
        ///
        /// ```rust
        /// # use clap::{Command, Arg, error::ErrorKind};
        /// let noerr = Command::new("myprog")
        ///     .subcommand_negates_reqs(true)
        ///     .arg(Arg::new("opt").required(true))
        ///     .subcommand(Command::new("test"))
        ///     .try_get_matches_from(vec![
        ///         "myprog", "test"
        ///     ]);
        /// assert!(noerr.is_ok());
        /// # ;
        /// ```
        ///
        /// [`Arg::required(true)`]: crate::Arg::required()
        /// [`subcommands`]: crate::Command::subcommand()
        pub fn subcommand_negates_reqs(self, yes: bool) -> Self {
            if yes {
                self.setting(AppSettings::SubcommandsNegateReqs)
            } else {
                self.unset_setting(AppSettings::SubcommandsNegateReqs)
            }
        }

        /// Multiple-personality program dispatched on the binary name (`argv[0]`)
        ///
        /// A "multicall" executable is a single executable
        /// that contains a variety of applets,
        /// and decides which applet to run based on the name of the file.
        /// The executable can be called from different names by creating hard links
        /// or symbolic links to it.
        ///
        /// This is desirable for:
        /// - Easy distribution, a single binary that can install hardlinks to access the different
        ///   personalities.
        /// - Minimal binary size by sharing common code (e.g. standard library, clap)
        /// - Custom shells or REPLs where there isn't a single top-level command
        ///
        /// Setting `multicall` will cause
        /// - `argv[0]` to be stripped to the base name and parsed as the first argument, as if
        ///   [`Command::no_binary_name`][Command::no_binary_name] was set.
        /// - Help and errors to report subcommands as if they were the top-level command
        ///
        /// When the subcommand is not present, there are several strategies you may employ, depending
        /// on your needs:
        /// - Let the error percolate up normally
        /// - Print a specialized error message using the
        ///   [`Error::context`][crate::Error::context]
        /// - Print the [help][Command::write_help] but this might be ambiguous
        /// - Disable `multicall` and re-parse it
        /// - Disable `multicall` and re-parse it with a specific subcommand
        ///
        /// When detecting the error condition, the [`ErrorKind`] isn't sufficient as a sub-subcommand
        /// might report the same error.  Enable
        /// [`allow_external_subcommands`][Command::allow_external_subcommands] if you want to specifically
        /// get the unrecognized binary name.
        ///
        /// **NOTE:** Multicall can't be used with [`no_binary_name`] since they interpret
        /// the command name in incompatible ways.
        ///
        /// **NOTE:** The multicall command cannot have arguments.
        ///
        /// **NOTE:** Applets are slightly semantically different from subcommands,
        /// so it's recommended to use [`Command::subcommand_help_heading`] and
        /// [`Command::subcommand_value_name`] to change the descriptive text as above.
        ///
        /// # Examples
        ///
        /// `hostname` is an example of a multicall executable.
        /// Both `hostname` and `dnsdomainname` are provided by the same executable
        /// and which behaviour to use is based on the executable file name.
        ///
        /// This is desirable when the executable has a primary purpose
        /// but there is related functionality that would be convenient to provide
        /// and implement it to be in the same executable.
        ///
        /// The name of the cmd is essentially unused
        /// and may be the same as the name of a subcommand.
        ///
        /// The names of the immediate subcommands of the Command
        /// are matched against the basename of the first argument,
        /// which is conventionally the path of the executable.
        ///
        /// This does not allow the subcommand to be passed as the first non-path argument.
        ///
        /// ```rust
        /// # use clap::{Command, error::ErrorKind};
        /// let mut cmd = Command::new("hostname")
        ///     .multicall(true)
        ///     .subcommand(Command::new("hostname"))
        ///     .subcommand(Command::new("dnsdomainname"));
        /// let m = cmd.try_get_matches_from_mut(&["/usr/bin/hostname", "dnsdomainname"]);
        /// assert!(m.is_err());
        /// assert_eq!(m.unwrap_err().kind(), ErrorKind::UnknownArgument);
        /// let m = cmd.get_matches_from(&["/usr/bin/dnsdomainname"]);
        /// assert_eq!(m.subcommand_name(), Some("dnsdomainname"));
        /// ```
        ///
        /// Busybox is another common example of a multicall executable
        /// with a subcommmand for each applet that can be run directly,
        /// e.g. with the `cat` applet being run by running `busybox cat`,
        /// or with `cat` as a link to the `busybox` binary.
        ///
        /// This is desirable when the launcher program has additional options
        /// or it is useful to run the applet without installing a symlink
        /// e.g. to test the applet without installing it
        /// or there may already be a command of that name installed.
        ///
        /// To make an applet usable as both a multicall link and a subcommand
        /// the subcommands must be defined both in the top-level Command
        /// and as subcommands of the "main" applet.
        ///
        /// ```rust
        /// # use clap::Command;
        /// fn applet_commands() -> [Command; 2] {
        ///     [Command::new("true"), Command::new("false")]
        /// }
        /// let mut cmd = Command::new("busybox")
        ///     .multicall(true)
        ///     .subcommand(
        ///         Command::new("busybox")
        ///             .subcommand_value_name("APPLET")
        ///             .subcommand_help_heading("APPLETS")
        ///             .subcommands(applet_commands()),
        ///     )
        ///     .subcommands(applet_commands());
        /// // When called from the executable's canonical name
        /// // its applets can be matched as subcommands.
        /// let m = cmd.try_get_matches_from_mut(&["/usr/bin/busybox", "true"]).unwrap();
        /// assert_eq!(m.subcommand_name(), Some("busybox"));
        /// assert_eq!(m.subcommand().unwrap().1.subcommand_name(), Some("true"));
        /// // When called from a link named after an applet that applet is matched.
        /// let m = cmd.get_matches_from(&["/usr/bin/true"]);
        /// assert_eq!(m.subcommand_name(), Some("true"));
        /// ```
        ///
        /// [`no_binary_name`]: crate::Command::no_binary_name
        /// [`Command::subcommand_value_name`]: crate::Command::subcommand_value_name
        /// [`Command::subcommand_help_heading`]: crate::Command::subcommand_help_heading
        #[inline]
        pub fn multicall(self, yes: bool) -> Self {
            if yes {
                self.setting(AppSettings::Multicall)
            } else {
                self.unset_setting(AppSettings::Multicall)
            }
        }

        /// Sets the value name used for subcommands when printing usage and help.
        ///
        /// By default, this is "COMMAND".
        ///
        /// See also [`Command::subcommand_help_heading`]
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// Command::new("myprog")
        ///     .subcommand(Command::new("sub1"))
        ///     .print_help()
        /// # ;
        /// ```
        ///
        /// will produce
        ///
        /// ```text
        /// myprog
        ///
        /// Usage: myprog [COMMAND]
        ///
        /// Commands:
        ///     help    Print this message or the help of the given subcommand(s)
        ///     sub1
        ///
        /// Options:
        ///     -h, --help       Print help information
        ///     -V, --version    Print version information
        /// ```
        ///
        /// but usage of `subcommand_value_name`
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// Command::new("myprog")
        ///     .subcommand(Command::new("sub1"))
        ///     .subcommand_value_name("THING")
        ///     .print_help()
        /// # ;
        /// ```
        ///
        /// will produce
        ///
        /// ```text
        /// myprog
        ///
        /// Usage: myprog [THING]
        ///
        /// Commands:
        ///     help    Print this message or the help of the given subcommand(s)
        ///     sub1
        ///
        /// Options:
        ///     -h, --help       Print help information
        ///     -V, --version    Print version information
        /// ```
        #[must_use]
        pub fn subcommand_value_name(mut self, value_name: impl IntoResettable<Str>) -> Self {
            self.subcommand_value_name = value_name.into_resettable().into_option();
            self
        }

        /// Sets the help heading used for subcommands when printing usage and help.
        ///
        /// By default, this is "Commands".
        ///
        /// See also [`Command::subcommand_value_name`]
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// Command::new("myprog")
        ///     .subcommand(Command::new("sub1"))
        ///     .print_help()
        /// # ;
        /// ```
        ///
        /// will produce
        ///
        /// ```text
        /// myprog
        ///
        /// Usage: myprog [COMMAND]
        ///
        /// Commands:
        ///     help    Print this message or the help of the given subcommand(s)
        ///     sub1
        ///
        /// Options:
        ///     -h, --help       Print help information
        ///     -V, --version    Print version information
        /// ```
        ///
        /// but usage of `subcommand_help_heading`
        ///
        /// ```no_run
        /// # use clap::{Command, Arg};
        /// Command::new("myprog")
        ///     .subcommand(Command::new("sub1"))
        ///     .subcommand_help_heading("Things")
        ///     .print_help()
        /// # ;
        /// ```
        ///
        /// will produce
        ///
        /// ```text
        /// myprog
        ///
        /// Usage: myprog [COMMAND]
        ///
        /// Things:
        ///     help    Print this message or the help of the given subcommand(s)
        ///     sub1
        ///
        /// Options:
        ///     -h, --help       Print help information
        ///     -V, --version    Print version information
        /// ```
        #[must_use]
        pub fn subcommand_help_heading(mut self, heading: impl IntoResettable<Str>) -> Self {
            self.subcommand_heading = heading.into_resettable().into_option();
            self
        }
    }

    /// # Reflection
    impl Command {
        #[inline]
        #[cfg(feature = "usage")]
        pub(crate) fn get_usage_name(&self) -> Option<&str> {
            self.usage_name.as_deref()
        }

        /// Get the name of the binary.
        #[inline]
        pub fn get_display_name(&self) -> Option<&str> {
            self.display_name.as_deref()
        }

        /// Get the name of the binary.
        #[inline]
        pub fn get_bin_name(&self) -> Option<&str> {
            self.bin_name.as_deref()
        }

        /// Set binary name. Uses `&mut self` instead of `self`.
        pub fn set_bin_name(&mut self, name: impl Into<String>) {
            self.bin_name = Some(name.into());
        }

        /// Get the name of the cmd.
        #[inline]
        pub fn get_name(&self) -> &str {
            self.name.as_str()
        }

        #[inline]
        #[cfg(debug_assertions)]
        pub(crate) fn get_name_str(&self) -> &Str {
            &self.name
        }

        /// Get the version of the cmd.
        #[inline]
        pub fn get_version(&self) -> Option<&str> {
            self.version.as_deref()
        }

        /// Get the long version of the cmd.
        #[inline]
        pub fn get_long_version(&self) -> Option<&str> {
            self.long_version.as_deref()
        }

        /// Get the authors of the cmd.
        #[inline]
        pub fn get_author(&self) -> Option<&str> {
            self.author.as_deref()
        }

        /// Get the short flag of the subcommand.
        #[inline]
        pub fn get_short_flag(&self) -> Option<char> {
            self.short_flag
        }

        /// Get the long flag of the subcommand.
        #[inline]
        pub fn get_long_flag(&self) -> Option<&str> {
            self.long_flag.as_deref()
        }

        /// Get the help message specified via [`Command::about`].
        ///
        /// [`Command::about`]: Command::about()
        #[inline]
        pub fn get_about(&self) -> Option<&StyledStr> {
            self.about.as_ref()
        }

        /// Get the help message specified via [`Command::long_about`].
        ///
        /// [`Command::long_about`]: Command::long_about()
        #[inline]
        pub fn get_long_about(&self) -> Option<&StyledStr> {
            self.long_about.as_ref()
        }

        /// Get the custom section heading specified via [`Command::next_help_heading`].
        ///
        /// [`Command::help_heading`]: Command::help_heading()
        #[inline]
        pub fn get_next_help_heading(&self) -> Option<&str> {
            self.current_help_heading.as_deref()
        }

        /// Iterate through the *visible* aliases for this subcommand.
        #[inline]
        pub fn get_visible_aliases(&self) -> impl Iterator<Item = &str> + '_ {
            self.aliases
                .iter()
                .filter(|(_, vis)| *vis)
                .map(|a| a.0.as_str())
        }

        /// Iterate through the *visible* short aliases for this subcommand.
        #[inline]
        pub fn get_visible_short_flag_aliases(&self) -> impl Iterator<Item = char> + '_ {
            self.short_flag_aliases
                .iter()
                .filter(|(_, vis)| *vis)
                .map(|a| a.0)
        }

        /// Iterate through the *visible* long aliases for this subcommand.
        #[inline]
        pub fn get_visible_long_flag_aliases(&self) -> impl Iterator<Item = &str> + '_ {
            self.long_flag_aliases
                .iter()
                .filter(|(_, vis)| *vis)
                .map(|a| a.0.as_str())
        }

        /// Iterate through the set of *all* the aliases for this subcommand, both visible and hidden.
        #[inline]
        pub fn get_all_aliases(&self) -> impl Iterator<Item = &str> + '_ {
            self.aliases.iter().map(|a| a.0.as_str())
        }

        /// Iterate through the set of *all* the short aliases for this subcommand, both visible and hidden.
        #[inline]
        pub fn get_all_short_flag_aliases(&self) -> impl Iterator<Item = char> + '_ {
            self.short_flag_aliases.iter().map(|a| a.0)
        }

        /// Iterate through the set of *all* the long aliases for this subcommand, both visible and hidden.
        #[inline]
        pub fn get_all_long_flag_aliases(&self) -> impl Iterator<Item = &str> + '_ {
            self.long_flag_aliases.iter().map(|a| a.0.as_str())
        }

        #[inline]
        pub(crate) fn is_set(&self, s: AppSettings) -> bool {
            self.settings.is_set(s) || self.g_settings.is_set(s)
        }

        /// Should we color the output?
        pub fn get_color(&self) -> ColorChoice {
            debug!("Command::color: Color setting...");

            if cfg!(feature = "color") {
                if self.is_set(AppSettings::ColorNever) {
                    debug!("Never");
                    ColorChoice::Never
                } else if self.is_set(AppSettings::ColorAlways) {
                    debug!("Always");
                    ColorChoice::Always
                } else {
                    debug!("Auto");
                    ColorChoice::Auto
                }
            } else {
                ColorChoice::Never
            }
        }

        /// Iterate through the set of subcommands, getting a reference to each.
        #[inline]
        pub fn get_subcommands(&self) -> impl Iterator<Item = &Command> {
            self.subcommands.iter()
        }

        /// Iterate through the set of subcommands, getting a mutable reference to each.
        #[inline]
        pub fn get_subcommands_mut(&mut self) -> impl Iterator<Item = &mut Command> {
            self.subcommands.iter_mut()
        }

        /// Returns `true` if this `Command` has subcommands.
        #[inline]
        pub fn has_subcommands(&self) -> bool {
            !self.subcommands.is_empty()
        }

        /// Returns the help heading for listing subcommands.
        #[inline]
        pub fn get_subcommand_help_heading(&self) -> Option<&str> {
            self.subcommand_heading.as_deref()
        }

        /// Returns the subcommand value name.
        #[inline]
        pub fn get_subcommand_value_name(&self) -> Option<&str> {
            self.subcommand_value_name.as_deref()
        }

        /// Returns the help heading for listing subcommands.
        #[inline]
        pub fn get_before_help(&self) -> Option<&StyledStr> {
            self.before_help.as_ref()
        }

        /// Returns the help heading for listing subcommands.
        #[inline]
        pub fn get_before_long_help(&self) -> Option<&StyledStr> {
            self.before_long_help.as_ref()
        }

        /// Returns the help heading for listing subcommands.
        #[inline]
        pub fn get_after_help(&self) -> Option<&StyledStr> {
            self.after_help.as_ref()
        }

        /// Returns the help heading for listing subcommands.
        #[inline]
        pub fn get_after_long_help(&self) -> Option<&StyledStr> {
            self.after_long_help.as_ref()
        }

        /// Find subcommand such that its name or one of aliases equals `name`.
        ///
        /// This does not recurse through subcommands of subcommands.
        #[inline]
        pub fn find_subcommand(&self, name: impl AsRef<std::ffi::OsStr>) -> Option<&Command> {
            let name = name.as_ref();
            self.get_subcommands().find(|s| s.aliases_to(name))
        }

        /// Find subcommand such that its name or one of aliases equals `name`, returning
        /// a mutable reference to the subcommand.
        ///
        /// This does not recurse through subcommands of subcommands.
        #[inline]
        pub fn find_subcommand_mut(
            &mut self,
            name: impl AsRef<std::ffi::OsStr>,
        ) -> Option<&mut Command> {
            let name = name.as_ref();
            self.get_subcommands_mut().find(|s| s.aliases_to(name))
        }

        /// Iterate through the set of groups.
        #[inline]
        pub fn get_groups(&self) -> impl Iterator<Item = &ArgGroup> {
            self.groups.iter()
        }

        /// Iterate through the set of arguments.
        #[inline]
        pub fn get_arguments(&self) -> impl Iterator<Item = &Arg> {
            self.args.args()
        }

        /// Iterate through the *positionals* arguments.
        #[inline]
        pub fn get_positionals(&self) -> impl Iterator<Item = &Arg> {
            self.get_arguments().filter(|a| a.is_positional())
        }

        /// Iterate through the *options*.
        pub fn get_opts(&self) -> impl Iterator<Item = &Arg> {
            self.get_arguments()
                .filter(|a| a.is_takes_value_set() && !a.is_positional())
        }

        /// Get a list of all arguments the given argument conflicts with.
        ///
        /// If the provided argument is declared as global, the conflicts will be determined
        /// based on the propagation rules of global arguments.
        ///
        /// ### Panics
        ///
        /// If the given arg contains a conflict with an argument that is unknown to
        /// this `Command`.
        pub fn get_arg_conflicts_with(&self, arg: &Arg) -> Vec<&Arg> // FIXME: This could probably have been an iterator
        {
            if arg.is_global_set() {
                self.get_global_arg_conflicts_with(arg)
            } else {
                let mut result = Vec::new();
                for id in arg.blacklist.iter() {
                    if let Some(arg) = self.find(id) {
                        result.push(arg);
                    } else if let Some(group) = self.find_group(id) {
                        result.extend(
                            self.unroll_args_in_group(&group.id)
                                .iter()
                                .map(|id| self.find(id).expect(INTERNAL_ERROR_MSG)),
                        );
                    } else {
                        panic!("Command::get_arg_conflicts_with: The passed arg conflicts with an arg unknown to the cmd");
                    }
                }
                result
            }
        }

        // Get a unique list of all arguments of all commands and continuous subcommands the given argument conflicts with.
        //
        // This behavior follows the propagation rules of global arguments.
        // It is useful for finding conflicts for arguments declared as global.
        //
        // ### Panics
        //
        // If the given arg contains a conflict with an argument that is unknown to
        // this `Command`.
        fn get_global_arg_conflicts_with(&self, arg: &Arg) -> Vec<&Arg> // FIXME: This could probably have been an iterator
        {
            arg.blacklist
                .iter()
                .map(|id| {
                    self.args
                        .args()
                        .chain(
                            self.get_subcommands_containing(arg)
                                .iter()
                                .flat_map(|x| x.args.args()),
                        )
                        .find(|arg| arg.get_id() == id)
                        .expect(
                            "Command::get_arg_conflicts_with: \
                        The passed arg conflicts with an arg unknown to the cmd",
                        )
                })
                .collect()
        }

        // Get a list of subcommands which contain the provided Argument
        //
        // This command will only include subcommands in its list for which the subcommands
        // parent also contains the Argument.
        //
        // This search follows the propagation rules of global arguments.
        // It is useful to finding subcommands, that have inherited a global argument.
        //
        // **NOTE:** In this case only Sucommand_1 will be included
        //   Subcommand_1 (contains Arg)
        //     Subcommand_1.1 (doesn't contain Arg)
        //       Subcommand_1.1.1 (contains Arg)
        //
        fn get_subcommands_containing(&self, arg: &Arg) -> Vec<&Self> {
            let mut vec = std::vec::Vec::new();
            for idx in 0..self.subcommands.len() {
                if self.subcommands[idx]
                    .args
                    .args()
                    .any(|ar| ar.get_id() == arg.get_id())
                {
                    vec.push(&self.subcommands[idx]);
                    vec.append(&mut self.subcommands[idx].get_subcommands_containing(arg));
                }
            }
            vec
        }

        /// Report whether [`Command::no_binary_name`] is set
        pub fn is_no_binary_name_set(&self) -> bool {
            self.is_set(AppSettings::NoBinaryName)
        }

        /// Report whether [`Command::ignore_errors`] is set
        pub(crate) fn is_ignore_errors_set(&self) -> bool {
            self.is_set(AppSettings::IgnoreErrors)
        }

        /// Report whether [`Command::dont_delimit_trailing_values`] is set
        pub fn is_dont_delimit_trailing_values_set(&self) -> bool {
            self.is_set(AppSettings::DontDelimitTrailingValues)
        }

        /// Report whether [`Command::disable_version_flag`] is set
        pub fn is_disable_version_flag_set(&self) -> bool {
            self.is_set(AppSettings::DisableVersionFlag)
                || (self.version.is_none() && self.long_version.is_none())
        }

        /// Report whether [`Command::propagate_version`] is set
        pub fn is_propagate_version_set(&self) -> bool {
            self.is_set(AppSettings::PropagateVersion)
        }

        /// Report whether [`Command::next_line_help`] is set
        pub fn is_next_line_help_set(&self) -> bool {
            self.is_set(AppSettings::NextLineHelp)
        }

        /// Report whether [`Command::disable_help_flag`] is set
        pub fn is_disable_help_flag_set(&self) -> bool {
            self.is_set(AppSettings::DisableHelpFlag)
        }

        /// Report whether [`Command::disable_help_subcommand`] is set
        pub fn is_disable_help_subcommand_set(&self) -> bool {
            self.is_set(AppSettings::DisableHelpSubcommand)
        }

        /// Report whether [`Command::disable_colored_help`] is set
        pub fn is_disable_colored_help_set(&self) -> bool {
            self.is_set(AppSettings::DisableColoredHelp)
        }

        /// Report whether [`Command::help_expected`] is set
        #[cfg(debug_assertions)]
        pub(crate) fn is_help_expected_set(&self) -> bool {
            self.is_set(AppSettings::HelpExpected)
        }

        #[doc(hidden)]
        #[cfg_attr(
            feature = "deprecated",
            deprecated(since = "4.0.0", note = "This is now the default")
        )]
        pub fn is_dont_collapse_args_in_usage_set(&self) -> bool {
            true
        }

        /// Report whether [`Command::infer_long_args`] is set
        pub(crate) fn is_infer_long_args_set(&self) -> bool {
            self.is_set(AppSettings::InferLongArgs)
        }

        /// Report whether [`Command::infer_subcommands`] is set
        pub(crate) fn is_infer_subcommands_set(&self) -> bool {
            self.is_set(AppSettings::InferSubcommands)
        }

        /// Report whether [`Command::arg_required_else_help`] is set
        pub fn is_arg_required_else_help_set(&self) -> bool {
            self.is_set(AppSettings::ArgRequiredElseHelp)
        }

        #[doc(hidden)]
        #[cfg_attr(
            feature = "deprecated",
            deprecated(
                since = "4.0.0",
                note = "Replaced with `Arg::is_allow_hyphen_values_set`"
            )
        )]
        pub(crate) fn is_allow_hyphen_values_set(&self) -> bool {
            self.is_set(AppSettings::AllowHyphenValues)
        }

        #[doc(hidden)]
        #[cfg_attr(
            feature = "deprecated",
            deprecated(
                since = "4.0.0",
                note = "Replaced with `Arg::is_allow_negative_numbers_set`"
            )
        )]
        pub fn is_allow_negative_numbers_set(&self) -> bool {
            self.is_set(AppSettings::AllowNegativeNumbers)
        }

        #[doc(hidden)]
        #[cfg_attr(
            feature = "deprecated",
            deprecated(since = "4.0.0", note = "Replaced with `Arg::is_trailing_var_arg_set`")
        )]
        pub fn is_trailing_var_arg_set(&self) -> bool {
            self.is_set(AppSettings::TrailingVarArg)
        }

        /// Report whether [`Command::allow_missing_positional`] is set
        pub fn is_allow_missing_positional_set(&self) -> bool {
            self.is_set(AppSettings::AllowMissingPositional)
        }

        /// Report whether [`Command::hide`] is set
        pub fn is_hide_set(&self) -> bool {
            self.is_set(AppSettings::Hidden)
        }

        /// Report whether [`Command::subcommand_required`] is set
        pub fn is_subcommand_required_set(&self) -> bool {
            self.is_set(AppSettings::SubcommandRequired)
        }

        /// Report whether [`Command::allow_external_subcommands`] is set
        pub fn is_allow_external_subcommands_set(&self) -> bool {
            self.is_set(AppSettings::AllowExternalSubcommands)
        }

        /// Configured parser for values passed to an external subcommand
        ///
        /// # Example
        ///
        /// ```rust
        /// let cmd = clap::Command::new("raw")
        ///     .external_subcommand_value_parser(clap::value_parser!(String));
        /// let value_parser = cmd.get_external_subcommand_value_parser();
        /// println!("{:?}", value_parser);
        /// ```
        pub fn get_external_subcommand_value_parser(&self) -> Option<&super::ValueParser> {
            if !self.is_allow_external_subcommands_set() {
                None
            } else {
                static DEFAULT: super::ValueParser = super::ValueParser::os_string();
                Some(self.external_value_parser.as_ref().unwrap_or(&DEFAULT))
            }
        }

        /// Report whether [`Command::args_conflicts_with_subcommands`] is set
        pub fn is_args_conflicts_with_subcommands_set(&self) -> bool {
            self.is_set(AppSettings::ArgsNegateSubcommands)
        }

        #[doc(hidden)]
        pub fn is_args_override_self(&self) -> bool {
            self.is_set(AppSettings::AllArgsOverrideSelf)
        }

        /// Report whether [`Command::subcommand_precedence_over_arg`] is set
        pub fn is_subcommand_precedence_over_arg_set(&self) -> bool {
            self.is_set(AppSettings::SubcommandPrecedenceOverArg)
        }

        /// Report whether [`Command::subcommand_negates_reqs`] is set
        pub fn is_subcommand_negates_reqs_set(&self) -> bool {
            self.is_set(AppSettings::SubcommandsNegateReqs)
        }

        /// Report whether [`Command::multicall`] is set
        pub fn is_multicall_set(&self) -> bool {
            self.is_set(AppSettings::Multicall)
        }
    }

    // Internally used only
    impl Command {
        pub(crate) fn get_override_usage(&self) -> Option<&StyledStr> {
            self.usage_str.as_ref()
        }

        pub(crate) fn get_override_help(&self) -> Option<&StyledStr> {
            self.help_str.as_ref()
        }

        #[cfg(feature = "help")]
        pub(crate) fn get_help_template(&self) -> Option<&StyledStr> {
            self.template.as_ref()
        }

        #[cfg(feature = "help")]
        pub(crate) fn get_term_width(&self) -> Option<usize> {
            self.term_w
        }

        #[cfg(feature = "help")]
        pub(crate) fn get_max_term_width(&self) -> Option<usize> {
            self.max_w
        }

        pub(crate) fn get_replacement(&self, key: &str) -> Option<&[Str]> {
            self.replacers.get(key).map(|v| v.as_slice())
        }

        pub(crate) fn get_keymap(&self) -> &MKeyMap {
            &self.args
        }

        fn get_used_global_args(&self, matches: &ArgMatches, global_arg_vec: &mut Vec<Id>) {
            global_arg_vec.extend(
                self.args
                    .args()
                    .filter(|a| a.is_global_set())
                    .map(|ga| ga.id.clone()),
            );
            if let Some((id, matches)) = matches.subcommand() {
                if let Some(used_sub) = self.find_subcommand(id) {
                    used_sub.get_used_global_args(matches, global_arg_vec);
                }
            }
        }

        fn _do_parse(
            &mut self,
            raw_args: &mut clap_lex::RawArgs,
            args_cursor: clap_lex::ArgCursor,
        ) -> ClapResult<ArgMatches> {
            debug!("Command::_do_parse");

            // If there are global arguments, or settings we need to propagate them down to subcommands
            // before parsing in case we run into a subcommand
            self._build_self(false);

            let mut matcher = ArgMatcher::new(self);

            // do the real parsing
            let mut parser = Parser::new(self);
            if let Err(error) = parser.get_matches_with(&mut matcher, raw_args, args_cursor) {
                if self.is_set(AppSettings::IgnoreErrors) {
                    debug!("Command::_do_parse: ignoring error: {}", error);
                } else {
                    return Err(error);
                }
            }

            let mut global_arg_vec = Default::default();
            self.get_used_global_args(&matcher, &mut global_arg_vec);

            matcher.propagate_globals(&global_arg_vec);

            Ok(matcher.into_inner())
        }

        /// Prepare for introspecting on all included [`Command`]s
        ///
        /// Call this on the top-level [`Command`] when done building and before reading state for
        /// cases like completions, custom help output, etc.
        pub fn build(&mut self) {
            self._build_recursive(true);
            self._build_bin_names_internal();
        }

        pub(crate) fn _build_recursive(&mut self, expand_help_tree: bool) {
            self._build_self(expand_help_tree);
            for subcmd in self.get_subcommands_mut() {
                subcmd._build_recursive(expand_help_tree);
            }
        }

        pub(crate) fn _build_self(&mut self, expand_help_tree: bool) {
            debug!("Command::_build: name={:?}", self.get_name());
            if !self.settings.is_set(AppSettings::Built) {
                // Make sure all the globally set flags apply to us as well
                self.settings = self.settings | self.g_settings;

                if self.is_multicall_set() {
                    self.settings.insert(AppSettings::SubcommandRequired.into());
                    self.settings.insert(AppSettings::DisableHelpFlag.into());
                    self.settings.insert(AppSettings::DisableVersionFlag.into());
                }
                if !cfg!(feature = "help") && self.get_override_help().is_none() {
                    self.settings.insert(AppSettings::DisableHelpFlag.into());
                    self.settings
                        .insert(AppSettings::DisableHelpSubcommand.into());
                }
                if self.is_set(AppSettings::ArgsNegateSubcommands) {
                    self.settings
                        .insert(AppSettings::SubcommandsNegateReqs.into());
                }
                if self.external_value_parser.is_some() {
                    self.settings
                        .insert(AppSettings::AllowExternalSubcommands.into());
                }
                if !self.has_subcommands() {
                    self.settings
                        .insert(AppSettings::DisableHelpSubcommand.into());
                }

                self._propagate();
                self._check_help_and_version(expand_help_tree);
                self._propagate_global_args();

                let mut pos_counter = 1;
                let hide_pv = self.is_set(AppSettings::HidePossibleValues);
                for a in self.args.args_mut() {
                    // Fill in the groups
                    for g in &a.groups {
                        if let Some(ag) = self.groups.iter_mut().find(|grp| grp.id == *g) {
                            ag.args.push(a.get_id().clone());
                        } else {
                            let mut ag = ArgGroup::new(g);
                            ag.args.push(a.get_id().clone());
                            self.groups.push(ag);
                        }
                    }

                    // Figure out implied settings
                    a._build();
                    if hide_pv && a.is_takes_value_set() {
                        a.settings.set(ArgSettings::HidePossibleValues);
                    }
                    if a.is_positional() && a.index.is_none() {
                        a.index = Some(pos_counter);
                        pos_counter += 1;
                    }
                }

                self.args._build();

                #[allow(deprecated)]
                {
                    let highest_idx = self
                        .get_keymap()
                        .keys()
                        .filter_map(|x| {
                            if let crate::mkeymap::KeyType::Position(n) = x {
                                Some(*n)
                            } else {
                                None
                            }
                        })
                        .max()
                        .unwrap_or(0);
                    let is_trailing_var_arg_set = self.is_trailing_var_arg_set();
                    let is_allow_hyphen_values_set = self.is_allow_hyphen_values_set();
                    let is_allow_negative_numbers_set = self.is_allow_negative_numbers_set();
                    for arg in self.args.args_mut() {
                        if is_allow_hyphen_values_set && arg.is_takes_value_set() {
                            arg.settings.insert(ArgSettings::AllowHyphenValues.into());
                        }
                        if is_allow_negative_numbers_set && arg.is_takes_value_set() {
                            arg.settings
                                .insert(ArgSettings::AllowNegativeNumbers.into());
                        }
                        if is_trailing_var_arg_set && arg.get_index() == Some(highest_idx) {
                            arg.settings.insert(ArgSettings::TrailingVarArg.into());
                        }
                    }
                }

                #[cfg(debug_assertions)]
                assert_app(self);
                self.settings.set(AppSettings::Built);
            } else {
                debug!("Command::_build: already built");
            }
        }

        pub(crate) fn _build_subcommand(&mut self, name: &str) -> Option<&mut Self> {
            use std::fmt::Write;

            let mut mid_string = String::from(" ");
            #[cfg(feature = "usage")]
            if !self.is_subcommand_negates_reqs_set() && !self.is_args_conflicts_with_subcommands_set()
            {
                let reqs = Usage::new(self).get_required_usage_from(&[], None, true); // maybe Some(m)

                for s in &reqs {
                    mid_string.push_str(&s.to_string());
                    mid_string.push(' ');
                }
            }
            let is_multicall_set = self.is_multicall_set();

            let sc = some!(self.subcommands.iter_mut().find(|s| s.name == name));

            // Display subcommand name, short and long in usage
            let mut sc_names = String::new();
            sc_names.push_str(sc.name.as_str());
            let mut flag_subcmd = false;
            if let Some(l) = sc.get_long_flag() {
                write!(sc_names, "|--{}", l).unwrap();
                flag_subcmd = true;
            }
            if let Some(s) = sc.get_short_flag() {
                write!(sc_names, "|-{}", s).unwrap();
                flag_subcmd = true;
            }

            if flag_subcmd {
                sc_names = format!("{{{}}}", sc_names);
            }

            let usage_name = self
                .bin_name
                .as_ref()
                .map(|bin_name| format!("{}{}{}", bin_name, mid_string, sc_names))
                .unwrap_or(sc_names);
            sc.usage_name = Some(usage_name);

            // bin_name should be parent's bin_name + [<reqs>] + the sc's name separated by
            // a space
            let bin_name = format!(
                "{}{}{}",
                self.bin_name.as_deref().unwrap_or_default(),
                if self.bin_name.is_some() { " " } else { "" },
                &*sc.name
            );
            debug!(
                "Command::_build_subcommand Setting bin_name of {} to {:?}",
                sc.name, bin_name
            );
            sc.bin_name = Some(bin_name);

            if sc.display_name.is_none() {
                let self_display_name = if is_multicall_set {
                    self.display_name.as_deref().unwrap_or("")
                } else {
                    self.display_name.as_deref().unwrap_or(&self.name)
                };
                let display_name = format!(
                    "{}{}{}",
                    self_display_name,
                    if !self_display_name.is_empty() {
                        "-"
                    } else {
                        ""
                    },
                    &*sc.name
                );
                debug!(
                    "Command::_build_subcommand Setting display_name of {} to {:?}",
                    sc.name, display_name
                );
                sc.display_name = Some(display_name);
            }

            // Ensure all args are built and ready to parse
            sc._build_self(false);

            Some(sc)
        }

        fn _build_bin_names_internal(&mut self) {
            debug!("Command::_build_bin_names");

            if !self.is_set(AppSettings::BinNameBuilt) {
                let mut mid_string = String::from(" ");
                #[cfg(feature = "usage")]
                if !self.is_subcommand_negates_reqs_set()
                    && !self.is_args_conflicts_with_subcommands_set()
                {
                    let reqs = Usage::new(self).get_required_usage_from(&[], None, true); // maybe Some(m)

                    for s in &reqs {
                        mid_string.push_str(&s.to_string());
                        mid_string.push(' ');
                    }
                }
                let is_multicall_set = self.is_multicall_set();

                let self_bin_name = if is_multicall_set {
                    self.bin_name.as_deref().unwrap_or("")
                } else {
                    self.bin_name.as_deref().unwrap_or(&self.name)
                }
                .to_owned();

                for mut sc in &mut self.subcommands {
                    debug!("Command::_build_bin_names:iter: bin_name set...");

                    if sc.usage_name.is_none() {
                        use std::fmt::Write;
                        // Display subcommand name, short and long in usage
                        let mut sc_names = String::new();
                        sc_names.push_str(sc.name.as_str());
                        let mut flag_subcmd = false;
                        if let Some(l) = sc.get_long_flag() {
                            write!(sc_names, "|--{}", l).unwrap();
                            flag_subcmd = true;
                        }
                        if let Some(s) = sc.get_short_flag() {
                            write!(sc_names, "|-{}", s).unwrap();
                            flag_subcmd = true;
                        }

                        if flag_subcmd {
                            sc_names = format!("{{{}}}", sc_names);
                        }

                        let usage_name = format!("{}{}{}", self_bin_name, mid_string, sc_names);
                        debug!(
                            "Command::_build_bin_names:iter: Setting usage_name of {} to {:?}",
                            sc.name, usage_name
                        );
                        sc.usage_name = Some(usage_name);
                    } else {
                        debug!(
                            "Command::_build_bin_names::iter: Using existing usage_name of {} ({:?})",
                            sc.name, sc.usage_name
                        );
                    }

                    if sc.bin_name.is_none() {
                        let bin_name = format!(
                            "{}{}{}",
                            self_bin_name,
                            if !self_bin_name.is_empty() { " " } else { "" },
                            &*sc.name
                        );
                        debug!(
                            "Command::_build_bin_names:iter: Setting bin_name of {} to {:?}",
                            sc.name, bin_name
                        );
                        sc.bin_name = Some(bin_name);
                    } else {
                        debug!(
                            "Command::_build_bin_names::iter: Using existing bin_name of {} ({:?})",
                            sc.name, sc.bin_name
                        );
                    }

                    if sc.display_name.is_none() {
                        let self_display_name = if is_multicall_set {
                            self.display_name.as_deref().unwrap_or("")
                        } else {
                            self.display_name.as_deref().unwrap_or(&self.name)
                        };
                        let display_name = format!(
                            "{}{}{}",
                            self_display_name,
                            if !self_display_name.is_empty() {
                                "-"
                            } else {
                                ""
                            },
                            &*sc.name
                        );
                        debug!(
                            "Command::_build_bin_names:iter: Setting display_name of {} to {:?}",
                            sc.name, display_name
                        );
                        sc.display_name = Some(display_name);
                    } else {
                        debug!(
                            "Command::_build_bin_names::iter: Using existing display_name of {} ({:?})",
                            sc.name, sc.display_name
                        );
                    }

                    sc._build_bin_names_internal();
                }
                self.set(AppSettings::BinNameBuilt);
            } else {
                debug!("Command::_build_bin_names: already built");
            }
        }

        pub(crate) fn _panic_on_missing_help(&self, help_required_globally: bool) {
            if self.is_set(AppSettings::HelpExpected) || help_required_globally {
                let args_missing_help: Vec<Id> = self
                    .args
                    .args()
                    .filter(|arg| arg.get_help().is_none() && arg.get_long_help().is_none())
                    .map(|arg| arg.get_id().clone())
                    .collect();

                debug_assert!(args_missing_help.is_empty(),
                        "Command::help_expected is enabled for the Command {}, but at least one of its arguments does not have either `help` or `long_help` set. List of such arguments: {}",
                        self.name,
                        args_missing_help.join(", ")
                    );
            }

            for sub_app in &self.subcommands {
                sub_app._panic_on_missing_help(help_required_globally);
            }
        }

        #[cfg(debug_assertions)]
        pub(crate) fn two_args_of<F>(&self, condition: F) -> Option<(&Arg, &Arg)>
        where
            F: Fn(&Arg) -> bool,
        {
            two_elements_of(self.args.args().filter(|a: &&Arg| condition(a)))
        }

        // just in case
        #[allow(unused)]
        fn two_groups_of<F>(&self, condition: F) -> Option<(&ArgGroup, &ArgGroup)>
        where
            F: Fn(&ArgGroup) -> bool,
        {
            two_elements_of(self.groups.iter().filter(|a| condition(a)))
        }

        /// Propagate global args
        pub(crate) fn _propagate_global_args(&mut self) {
            debug!("Command::_propagate_global_args:{}", self.name);

            let autogenerated_help_subcommand = !self.is_disable_help_subcommand_set();

            for sc in &mut self.subcommands {
                if sc.get_name() == "help" && autogenerated_help_subcommand {
                    // Avoid propagating args to the autogenerated help subtrees used in completion.
                    // This prevents args from showing up during help completions like
                    // `myapp help subcmd <TAB>`, which should only suggest subcommands and not args,
                    // while still allowing args to show up properly on the generated help message.
                    continue;
                }

                for a in self.args.args().filter(|a| a.is_global_set()) {
                    if sc.find(&a.id).is_some() {
                        debug!(
                            "Command::_propagate skipping {:?} to {}, already exists",
                            a.id,
                            sc.get_name(),
                        );
                        continue;
                    }

                    debug!(
                        "Command::_propagate pushing {:?} to {}",
                        a.id,
                        sc.get_name(),
                    );
                    sc.args.push(a.clone());
                }
            }
        }

        /// Propagate settings
        pub(crate) fn _propagate(&mut self) {
            debug!("Command::_propagate:{}", self.name);
            let mut subcommands = std::mem::take(&mut self.subcommands);
            for sc in &mut subcommands {
                self._propagate_subcommand(sc);
            }
            self.subcommands = subcommands;
        }

        fn _propagate_subcommand(&self, sc: &mut Self) {
            // We have to create a new scope in order to tell rustc the borrow of `sc` is
            // done and to recursively call this method
            {
                if self.settings.is_set(AppSettings::PropagateVersion) {
                    if let Some(version) = self.version.as_ref() {
                        sc.version.get_or_insert_with(|| version.clone());
                    }
                    if let Some(long_version) = self.long_version.as_ref() {
                        sc.long_version.get_or_insert_with(|| long_version.clone());
                    }
                }

                sc.settings = sc.settings | self.g_settings;
                sc.g_settings = sc.g_settings | self.g_settings;
                sc.term_w = self.term_w;
                sc.max_w = self.max_w;
            }
        }

        pub(crate) fn _check_help_and_version(&mut self, expand_help_tree: bool) {
            debug!(
                "Command::_check_help_and_version:{} expand_help_tree={}",
                self.name, expand_help_tree
            );

            self.long_help_exists = self.long_help_exists_();

            if !self.is_disable_help_flag_set() {
                debug!("Command::_check_help_and_version: Building default --help");
                let mut arg = Arg::new(Id::HELP)
                    .short('h')
                    .long("help")
                    .action(ArgAction::Help);
                if self.long_help_exists {
                    arg = arg
                        .help("Print help information (use `--help` for more detail)")
                        .long_help("Print help information (use `-h` for a summary)");
                } else {
                    arg = arg.help("Print help information");
                }
                // Avoiding `arg_internal` to not be sensitive to `next_help_heading` /
                // `next_display_order`
                self.args.push(arg);
            }
            if !self.is_disable_version_flag_set() {
                debug!("Command::_check_help_and_version: Building default --version");
                let arg = Arg::new(Id::VERSION)
                    .short('V')
                    .long("version")
                    .action(ArgAction::Version)
                    .help("Print version information");
                // Avoiding `arg_internal` to not be sensitive to `next_help_heading` /
                // `next_display_order`
                self.args.push(arg);
            }

            if !self.is_set(AppSettings::DisableHelpSubcommand) {
                debug!("Command::_check_help_and_version: Building help subcommand");
                let help_about = "Print this message or the help of the given subcommand(s)";

                let mut help_subcmd = if expand_help_tree {
                    // Slow code path to recursively clone all other subcommand subtrees under help
                    let help_subcmd = Command::new("help")
                        .about(help_about)
                        .global_setting(AppSettings::DisableHelpSubcommand)
                        .subcommands(self.get_subcommands().map(Command::_copy_subtree_for_help));

                    let mut help_help_subcmd = Command::new("help").about(help_about);
                    help_help_subcmd.version = None;
                    help_help_subcmd.long_version = None;
                    help_help_subcmd = help_help_subcmd
                        .setting(AppSettings::DisableHelpFlag)
                        .setting(AppSettings::DisableVersionFlag);

                    help_subcmd.subcommand(help_help_subcmd)
                } else {
                    Command::new("help").about(help_about).arg(
                        Arg::new("subcommand")
                            .action(ArgAction::Append)
                            .num_args(..)
                            .value_name("COMMAND")
                            .help("Print help for the subcommand(s)"),
                    )
                };
                self._propagate_subcommand(&mut help_subcmd);

                // The parser acts like this is set, so let's set it so we don't falsely
                // advertise it to the user
                help_subcmd.version = None;
                help_subcmd.long_version = None;
                help_subcmd = help_subcmd
                    .setting(AppSettings::DisableHelpFlag)
                    .setting(AppSettings::DisableVersionFlag)
                    .unset_global_setting(AppSettings::PropagateVersion);

                self.subcommands.push(help_subcmd);
            }
        }

        fn _copy_subtree_for_help(&self) -> Command {
            let mut cmd = Command::new(self.name.clone())
                .hide(self.is_hide_set())
                .global_setting(AppSettings::DisableHelpFlag)
                .global_setting(AppSettings::DisableVersionFlag)
                .subcommands(self.get_subcommands().map(Command::_copy_subtree_for_help));
            if self.get_about().is_some() {
                cmd = cmd.about(self.get_about().unwrap().clone());
            }
            cmd
        }

        pub(crate) fn _render_version(&self, use_long: bool) -> String {
            debug!("Command::_render_version");

            let ver = if use_long {
                self.long_version
                    .as_deref()
                    .or(self.version.as_deref())
                    .unwrap_or_default()
            } else {
                self.version
                    .as_deref()
                    .or(self.long_version.as_deref())
                    .unwrap_or_default()
            };
            let display_name = self.get_display_name().unwrap_or_else(|| self.get_name());
            format!("{} {}\n", display_name, ver)
        }

        pub(crate) fn format_group(&self, g: &Id) -> StyledStr {
            let g_string = self
                .unroll_args_in_group(g)
                .iter()
                .filter_map(|x| self.find(x))
                .map(|x| {
                    if x.is_positional() {
                        // Print val_name for positional arguments. e.g. <file_name>
                        x.name_no_brackets()
                    } else {
                        // Print usage string for flags arguments, e.g. <--help>
                        x.to_string()
                    }
                })
                .collect::<Vec<_>>()
                .join("|");
            let mut styled = StyledStr::new();
            styled.none("<");
            styled.none(g_string);
            styled.none(">");
            styled
        }
    }

    /// A workaround:
    /// <https://github.com/rust-lang/rust/issues/34511#issuecomment-373423999>
    pub(crate) trait Captures<'a> {}
    impl<'a, T> Captures<'a> for T {}

    // Internal Query Methods
    impl Command {
        /// Iterate through the *flags* & *options* arguments.
        #[cfg(any(feature = "usage", feature = "help"))]
        pub(crate) fn get_non_positionals(&self) -> impl Iterator<Item = &Arg> {
            self.get_arguments().filter(|a| !a.is_positional())
        }

        pub(crate) fn find(&self, arg_id: &Id) -> Option<&Arg> {
            self.args.args().find(|a| a.get_id() == arg_id)
        }

        #[inline]
        pub(crate) fn contains_short(&self, s: char) -> bool {
            debug_assert!(
                self.is_set(AppSettings::Built),
                "If Command::_build hasn't been called, manually search through Arg shorts"
            );

            self.args.contains(s)
        }

        #[inline]
        pub(crate) fn set(&mut self, s: AppSettings) {
            self.settings.set(s)
        }

        #[inline]
        pub(crate) fn has_positionals(&self) -> bool {
            self.get_positionals().next().is_some()
        }

        #[cfg(any(feature = "usage", feature = "help"))]
        pub(crate) fn has_visible_subcommands(&self) -> bool {
            self.subcommands
                .iter()
                .any(|sc| sc.name != "help" && !sc.is_set(AppSettings::Hidden))
        }

        /// Check if this subcommand can be referred to as `name`. In other words,
        /// check if `name` is the name of this subcommand or is one of its aliases.
        #[inline]
        pub(crate) fn aliases_to(&self, name: impl AsRef<std::ffi::OsStr>) -> bool {
            let name = name.as_ref();
            self.get_name() == name || self.get_all_aliases().any(|alias| alias == name)
        }

        /// Check if this subcommand can be referred to as `name`. In other words,
        /// check if `name` is the name of this short flag subcommand or is one of its short flag aliases.
        #[inline]
        pub(crate) fn short_flag_aliases_to(&self, flag: char) -> bool {
            Some(flag) == self.short_flag
                || self.get_all_short_flag_aliases().any(|alias| flag == alias)
        }

        /// Check if this subcommand can be referred to as `name`. In other words,
        /// check if `name` is the name of this long flag subcommand or is one of its long flag aliases.
        #[inline]
        pub(crate) fn long_flag_aliases_to(&self, flag: &str) -> bool {
            match self.long_flag.as_ref() {
                Some(long_flag) => {
                    long_flag == flag || self.get_all_long_flag_aliases().any(|alias| alias == flag)
                }
                None => self.get_all_long_flag_aliases().any(|alias| alias == flag),
            }
        }

        #[cfg(debug_assertions)]
        pub(crate) fn id_exists(&self, id: &Id) -> bool {
            self.args.args().any(|x| x.get_id() == id) || self.groups.iter().any(|x| x.id == *id)
        }

        /// Iterate through the groups this arg is member of.
        pub(crate) fn groups_for_arg<'a>(&'a self, arg: &Id) -> impl Iterator<Item = Id> + 'a {
            debug!("Command::groups_for_arg: id={:?}", arg);
            let arg = arg.clone();
            self.groups
                .iter()
                .filter(move |grp| grp.args.iter().any(|a| a == &arg))
                .map(|grp| grp.id.clone())
        }

        pub(crate) fn find_group(&self, group_id: &Id) -> Option<&ArgGroup> {
            self.groups.iter().find(|g| g.id == *group_id)
        }

        /// Iterate through all the names of all subcommands (not recursively), including aliases.
        /// Used for suggestions.
        pub(crate) fn all_subcommand_names(&self) -> impl Iterator<Item = &str> + Captures {
            self.get_subcommands().flat_map(|sc| {
                let name = sc.get_name();
                let aliases = sc.get_all_aliases();
                std::iter::once(name).chain(aliases)
            })
        }

        pub(crate) fn required_graph(&self) -> ChildGraph<Id> {
            let mut reqs = ChildGraph::with_capacity(5);
            for a in self.args.args().filter(|a| a.is_required_set()) {
                reqs.insert(a.get_id().clone());
            }
            for group in &self.groups {
                if group.required {
                    let idx = reqs.insert(group.id.clone());
                    for a in &group.requires {
                        reqs.insert_child(idx, a.clone());
                    }
                }
            }

            reqs
        }

        pub(crate) fn unroll_args_in_group(&self, group: &Id) -> Vec<Id> {
            debug!("Command::unroll_args_in_group: group={:?}", group);
            let mut g_vec = vec![group];
            let mut args = vec![];

            while let Some(g) = g_vec.pop() {
                for n in self
                    .groups
                    .iter()
                    .find(|grp| grp.id == *g)
                    .expect(INTERNAL_ERROR_MSG)
                    .args
                    .iter()
                {
                    debug!("Command::unroll_args_in_group:iter: entity={:?}", n);
                    if !args.contains(n) {
                        if self.find(n).is_some() {
                            debug!("Command::unroll_args_in_group:iter: this is an arg");
                            args.push(n.clone())
                        } else {
                            debug!("Command::unroll_args_in_group:iter: this is a group");
                            g_vec.push(n);
                        }
                    }
                }
            }

            args
        }

        pub(crate) fn unroll_arg_requires<F>(&self, func: F, arg: &Id) -> Vec<Id>
        where
            F: Fn(&(ArgPredicate, Id)) -> Option<Id>,
        {
            let mut processed = vec![];
            let mut r_vec = vec![arg];
            let mut args = vec![];

            while let Some(a) = r_vec.pop() {
                if processed.contains(&a) {
                    continue;
                }

                processed.push(a);

                if let Some(arg) = self.find(a) {
                    for r in arg.requires.iter().filter_map(&func) {
                        if let Some(req) = self.find(&r) {
                            if !req.requires.is_empty() {
                                r_vec.push(req.get_id())
                            }
                        }
                        args.push(r);
                    }
                }
            }

            args
        }

        /// Find a flag subcommand name by short flag or an alias
        pub(crate) fn find_short_subcmd(&self, c: char) -> Option<&str> {
            self.get_subcommands()
                .find(|sc| sc.short_flag_aliases_to(c))
                .map(|sc| sc.get_name())
        }

        /// Find a flag subcommand name by long flag or an alias
        pub(crate) fn find_long_subcmd(&self, long: &str) -> Option<&str> {
            self.get_subcommands()
                .find(|sc| sc.long_flag_aliases_to(long))
                .map(|sc| sc.get_name())
        }

        #[cfg(feature = "help")]
        pub(crate) fn get_display_order(&self) -> usize {
            self.disp_ord.unwrap_or(999)
        }

        pub(crate) fn write_help_err(&self, mut use_long: bool) -> StyledStr {
            debug!(
                "Command::write_help_err: {}, use_long={:?}",
                self.get_display_name().unwrap_or_else(|| self.get_name()),
                use_long && self.long_help_exists(),
            );

            use_long = use_long && self.long_help_exists();
            let usage = Usage::new(self);

            let mut styled = StyledStr::new();
            write_help(&mut styled, self, &usage, use_long);

            styled
        }

        pub(crate) fn write_version_err(&self, use_long: bool) -> StyledStr {
            let msg = self._render_version(use_long);
            let mut styled = StyledStr::new();
            styled.none(msg);
            styled
        }

        pub(crate) fn long_help_exists(&self) -> bool {
            debug!("Command::long_help_exists: {}", self.long_help_exists);
            self.long_help_exists
        }

        fn long_help_exists_(&self) -> bool {
            debug!("Command::long_help_exists");
            // In this case, both must be checked. This allows the retention of
            // original formatting, but also ensures that the actual -h or --help
            // specified by the user is sent through. If hide_short_help is not included,
            // then items specified with hidden_short_help will also be hidden.
            let should_long = |v: &Arg| {
                v.get_long_help().is_some()
                    || v.is_hide_long_help_set()
                    || v.is_hide_short_help_set()
                    || v.get_possible_values()
                        .iter()
                        .any(PossibleValue::should_show_help)
            };

            // Subcommands aren't checked because we prefer short help for them, deferring to
            // `cmd subcmd --help` for more.
            self.get_long_about().is_some()
                || self.get_before_long_help().is_some()
                || self.get_after_long_help().is_some()
                || self.get_arguments().any(should_long)
        }

        // Should we color the help?
        pub(crate) fn color_help(&self) -> ColorChoice {
            #[cfg(feature = "color")]
            if self.is_disable_colored_help_set() {
                return ColorChoice::Never;
            }

            self.get_color()
        }
    }

    impl Default for Command {
        fn default() -> Self {
            Self {
                name: Default::default(),
                long_flag: Default::default(),
                short_flag: Default::default(),
                display_name: Default::default(),
                bin_name: Default::default(),
                author: Default::default(),
                version: Default::default(),
                long_version: Default::default(),
                about: Default::default(),
                long_about: Default::default(),
                before_help: Default::default(),
                before_long_help: Default::default(),
                after_help: Default::default(),
                after_long_help: Default::default(),
                aliases: Default::default(),
                short_flag_aliases: Default::default(),
                long_flag_aliases: Default::default(),
                usage_str: Default::default(),
                usage_name: Default::default(),
                help_str: Default::default(),
                disp_ord: Default::default(),
                term_w: Default::default(),
                max_w: Default::default(),
                #[cfg(feature = "help")]
                template: Default::default(),
                settings: Default::default(),
                g_settings: Default::default(),
                args: Default::default(),
                subcommands: Default::default(),
                replacers: Default::default(),
                groups: Default::default(),
                current_help_heading: Default::default(),
                current_disp_ord: Some(0),
                subcommand_value_name: Default::default(),
                subcommand_heading: Default::default(),
                external_value_parser: Default::default(),
                long_help_exists: false,
            }
        }
    }

    impl Index<&'_ Id> for Command {
        type Output = Arg;

        fn index(&self, key: &Id) -> &Self::Output {
            self.find(key).expect(INTERNAL_ERROR_MSG)
        }
    }

    impl From<&'_ Command> for Command {
        fn from(cmd: &'_ Command) -> Self {
            cmd.clone()
        }
    }

    impl fmt::Display for Command {
        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
            write!(f, "{}", self.name)
        }
    }

    fn two_elements_of<I, T>(mut iter: I) -> Option<(T, T)>
    where
        I: Iterator<Item = T>,
    {
        let first = iter.next();
        let second = iter.next();

        match (first, second) {
            (Some(first), Some(second)) => Some((first, second)),
            _ => None,
        }
    }

    #[test]
    fn check_auto_traits() {
        static_assertions::assert_impl_all!(Command: Send, Sync, Unpin);
    }