Merging upstream version 1.70.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 4670 insertions, 0 deletions

diff --git a/vendor/clap_builder/src/builder/command.rs b/vendor/clap_builder/src/builder/command.rs
new file mode 100644
index 000000000..34c04b425
--- /dev/null
+++ b/vendor/clap_builder/src/builder/command.rs
@@ -0,0 +1,4670 @@
+#![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::{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_builder as clap;
+/// # 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>,
+    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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # use clap::{Command, arg, Arg};
+    /// Command::new("myprog")
+    ///     .args([
+    ///         arg!(-d --debug "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_builder as clap;
+    /// # 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 `{id}` is undefined"));
+
+        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_builder as clap;
+    /// # 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 `{name}` is undefined")
+        };
+
+        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.
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # use clap::{Command, arg, ArgGroup};
+    /// Command::new("cmd")
+    ///     .arg(arg!(--"set-ver" <ver> "set the version manually").required(false))
+    ///     .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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # use clap::{Command, arg, ArgGroup};
+    /// Command::new("cmd")
+    ///     .arg(arg!(--"set-ver" <ver> "set the version manually").required(false))
+    ///     .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").required(false))
+    ///     .arg(arg!(-i <IFACE>      "an interface").required(false))
+    ///     .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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_flag("bar"));
+    /// }
+    /// ```
+    pub fn debug_assert(mut self) {
+        self.build();
+    }
+
+    /// Custom error message for post-parsing validation
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_flag("f"));
+    /// 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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 current
+    /// width 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
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # use clap::{Command, Arg};
+    /// Command::new("myprog")
+    ///     .override_usage("myapp [-clDas] <some_file>")
+    /// # ;
+    /// ```
+    ///
+    /// Or for multiple usage lines:
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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.
+    ///   * `{tab}`                 - 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:
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # use clap::Command;
+    /// Command::new("myprog")
+    ///     .version("1.0")
+    ///     .help_template("{name} ({version}) - {usage}")
+    /// # ;
+    /// ```
+    ///
+    /// For showing more application context:
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    }
+
+    /// Exit gracefully if no arguments are present (e.g. `$ myprog`).
+    ///
+    /// **NOTE:** [`subcommands`] count as arguments
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_flag("search"));
+    /// ```
+    /// [`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).
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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_flag("search"));
+    /// ```
+    ///
+    /// [`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_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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 order they are defined.
+    ///
+    /// 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
+    ///
+    /// ```rust
+    /// # #[cfg(feature = "help")] {
+    /// # use clap_builder as clap;
+    /// # 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
+    ///     -V, --version    Print version
+    /// ```
+    #[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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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 clap_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # #[cfg(unix)] {
+    /// # use clap_builder as clap;
+    /// # 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"]);
+    ///     },
+    ///     _ => {},
+    /// }
+    /// # }
+    /// ```
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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_builder as clap;
+    /// # 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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///     -V, --version    Print version
+    /// ```
+    ///
+    /// but usage of `subcommand_value_name`
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///     -V, --version    Print version
+    /// ```
+    #[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
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///     -V, --version    Print version
+    /// ```
+    ///
+    /// but usage of `subcommand_help_heading`
+    ///
+    /// ```rust
+    /// # use clap_builder as clap;
+    /// # 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
+    ///     -V, --version    Print version
+    /// ```
+    #[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
+    /// # use clap_builder as clap;
+    /// 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_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 (see more with '--help')")
+                    .long_help("Print help (see a summary with '-h')");
+            } else {
+                arg = arg.help("Print help");
+            }
+            // 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");
+            // 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!("{display_name} {ver}\n")
+    }
+
+    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);
+        StyledStr::from(msg)
+    }
+
+    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.is_hide_set()
+                && (v.get_long_help().is_some()
+                    || v.is_hide_long_help_set()
+                    || v.is_hide_short_help_set()
+                    || (!v.is_hide_possible_values_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(),
+            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);
+}