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    531

    use std::str::FromStr;
    use std::ascii::AsciiExt;

    bitflags! {
        flags Flags: u32 {
            const SC_NEGATE_REQS       = 0b00000000000000000000001,
            const SC_REQUIRED          = 0b00000000000000000000010,
            const A_REQUIRED_ELSE_HELP = 0b00000000000000000000100,
            const GLOBAL_VERSION       = 0b00000000000000000001000,
            const VERSIONLESS_SC       = 0b00000000000000000010000,
            const UNIFIED_HELP         = 0b00000000000000000100000,
            const WAIT_ON_ERROR        = 0b00000000000000001000000,
            const SC_REQUIRED_ELSE_HELP= 0b00000000000000010000000,
            const NEEDS_LONG_HELP      = 0b00000000000000100000000,
            const NEEDS_LONG_VERSION   = 0b00000000000001000000000,
            const NEEDS_SC_HELP        = 0b00000000000010000000000,
            const DISABLE_VERSION      = 0b00000000000100000000000,
            const HIDDEN               = 0b00000000001000000000000,
            const TRAILING_VARARG      = 0b00000000010000000000000,
            const NO_BIN_NAME          = 0b00000000100000000000000,
            const ALLOW_UNK_SC         = 0b00000001000000000000000,
            const UTF8_STRICT          = 0b00000010000000000000000,
            const UTF8_NONE            = 0b00000100000000000000000,
            const LEADING_HYPHEN       = 0b00001000000000000000000,
            const NO_POS_VALUES        = 0b00010000000000000000000,
            const NEXT_LINE_HELP       = 0b00100000000000000000000,
            const DERIVE_DISP_ORDER    = 0b01000000000000000000000,
            const COLORED_HELP         = 0b10000000000000000000000,
        }
    }

    #[doc(hidden)]
    #[derive(Debug)]
    pub struct AppFlags(Flags);

    impl Clone for AppFlags {
        fn clone(&self) -> Self {
            AppFlags(self.0)
        }
    }

    impl Default for AppFlags {
        fn default() -> Self {
            AppFlags(NEEDS_LONG_VERSION | NEEDS_LONG_HELP | NEEDS_SC_HELP | UTF8_NONE)
        }
    }

    impl AppFlags {
        pub fn new() -> Self {
            AppFlags::default()
        }

        impl_settings! { AppSettings,
            SubcommandsNegateReqs => SC_NEGATE_REQS,
            VersionlessSubcommands => VERSIONLESS_SC,
            SubcommandRequired => SC_REQUIRED,
            ArgRequiredElseHelp => A_REQUIRED_ELSE_HELP,
            GlobalVersion => GLOBAL_VERSION,
            UnifiedHelpMessage => UNIFIED_HELP,
            WaitOnError => WAIT_ON_ERROR,
            SubcommandRequiredElseHelp => SC_REQUIRED_ELSE_HELP,
            NeedsLongHelp => NEEDS_LONG_HELP,
            NeedsLongVersion => NEEDS_LONG_VERSION,
            NeedsSubcommandHelp => NEEDS_SC_HELP,
            DisableVersion => DISABLE_VERSION,
            Hidden => HIDDEN,
            TrailingVarArg => TRAILING_VARARG,
            NoBinaryName => NO_BIN_NAME,
            AllowExternalSubcommands => ALLOW_UNK_SC,
            StrictUtf8 => UTF8_STRICT,
            AllowInvalidUtf8 => UTF8_NONE,
            AllowLeadingHyphen => LEADING_HYPHEN,
            HidePossibleValuesInHelp => NO_POS_VALUES,
            NextLineHelp => NEXT_LINE_HELP,
            ColoredHelp => COLORED_HELP,
            DeriveDisplayOrder => DERIVE_DISP_ORDER
        }
    }

    /// Application level settings, which affect how `App` operates
    ///
    /// **NOTE:** When these settings are used, they apply only to current command, and are *not*
    /// propagated down or up through child or parent subcommands
    #[derive(Debug, PartialEq, Copy, Clone)]
    pub enum AppSettings {
        /// Allows subcommands to override all requirements of the parent command. For example
        /// if you had a subcommand or top level application which had a required argument that
        /// are only required as long as there is no subcommand present, using this setting would allow
        /// you set those arguments to `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::{App, Arg, AppSettings, SubCommand, ErrorKind};
        /// let err = App::new("myprog")
        ///     .setting(AppSettings::SubcommandsNegateReqs)
        ///     .arg(Arg::with_name("opt").required(true))
        ///     .subcommand(SubCommand::with_name("test"))
        ///     .get_matches_from_safe(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::{App, Arg, AppSettings, SubCommand, ErrorKind};
        /// let noerr = App::new("myprog")
        ///     .setting(AppSettings::SubcommandsNegateReqs)
        ///     .arg(Arg::with_name("opt").required(true))
        ///     .subcommand(SubCommand::with_name("test"))
        ///     .get_matches_from_safe(vec![
        ///         "myprog", "test"
        ///     ]);
        /// assert!(noerr.is_ok());
        /// # ;
        /// ```
        SubcommandsNegateReqs,
        /// Allows specifying that if no subcommand is present at runtime, error and exit gracefully
        ///
        /// **NOTE:** This defaults to false (subcommands do *not* need to be present)
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{App, AppSettings, SubCommand, ErrorKind};
        /// let err = App::new("myprog")
        ///     .setting(AppSettings::SubcommandRequired)
        ///     .subcommand(SubCommand::with_name("test"))
        ///     .get_matches_from_safe(vec![
        ///         "myprog",
        ///     ]);
        /// assert!(err.is_err());
        /// assert_eq!(err.unwrap_err().kind, ErrorKind::MissingSubcommand);
        /// # ;
        /// ```
        SubcommandRequired,
        /// Specifies that the help text should be displayed (and then exit gracefully), if no
        /// arguments are present at runtime (i.e. an empty run such as, `$ myprog`.
        ///
        /// **NOTE:** Subcommands count as arguments
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{App, AppSettings};
        /// App::new("myprog")
        ///     .setting(AppSettings::ArgRequiredElseHelp)
        /// # ;
        /// ```
        ArgRequiredElseHelp,
        /// Specifies to version of the current command for all child subcommands. (Defaults to false;
        /// subcommands have independant version strings from their parents)
        ///
        /// **NOTE:** The version for the current command **and** this setting must be set **prior** to
        /// adding any child subcommands
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{App, Arg, SubCommand, AppSettings};
        /// App::new("myprog")
        ///     .version("v1.1")
        ///     .setting(AppSettings::GlobalVersion)
        ///     .subcommand(SubCommand::with_name("test"))
        ///     .get_matches();
        /// // running `$ myprog test --version` will display
        /// // "myprog-test v1.1"
        /// ```
        GlobalVersion,
        /// Disables `-V` and `--version` for all subcommands (Defaults to false; subcommands have
        /// version flags)
        ///
        /// **NOTE:** This setting must be set **prior** adding any subcommands
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{App, SubCommand, AppSettings, ErrorKind};
        /// let res = App::new("myprog")
        ///     .version("v1.1")
        ///     .setting(AppSettings::VersionlessSubcommands)
        ///     .subcommand(SubCommand::with_name("test"))
        ///     .get_matches_from_safe(vec![
        ///         "myprog", "test", "-V"
        ///     ]);
        /// assert!(res.is_err());
        /// assert_eq!(res.unwrap_err().kind, ErrorKind::UnknownArgument);
        /// ```
        VersionlessSubcommands,
        /// Groups flags and options together presenting a more unified help message (a la `getopts` or
        /// `docopt` style). The default is the auto-generated help message groups flags, options
        /// separately.
        ///
        /// **NOTE:** This setting is cosmetic only and does not affect any functionality.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{App, Arg, SubCommand, AppSettings};
        /// App::new("myprog")
        ///     .setting(AppSettings::UnifiedHelpMessage)
        ///     .get_matches();
        /// // running `myprog --help` will display a unified "docopt" or "getopts" style help message
        /// ```
        UnifiedHelpMessage,
        /// Will display a message "Press [ENTER]/[RETURN] to continue..." and wait user before
        /// exiting
        ///
        /// This is most useful when writing an application which is run from a GUI shortcut, or on
        /// Windows where a user tries to open the binary by double-clicking instead of using the
        /// command line.
        ///
        /// **NOTE:** This setting is **not** recursive with subcommands, meaning if you wish this
        /// behavior for all subcommands, you must set this on each command (needing this is extremely
        /// rare)
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{App, Arg, AppSettings};
        /// App::new("myprog")
        ///     .setting(AppSettings::WaitOnError)
        /// # ;
        /// ```
        WaitOnError,
        /// Specifies that the help text should be displayed (and then exit gracefully), if no
        /// subcommands are present at runtime (i.e. an empty run such as, `$ myprog`.
        ///
        /// **NOTE:** This should *not* be used with `.subcommand_required()` as they do the same
        /// thing, except this prints the help text, and the other prints an error.
        ///
        /// **NOTE:** If the user specifies arguments at runtime, but no subcommand the help text will
        /// still be displayed and exit. If this is *not* the desired result, consider using
        /// `ArgRequiredElseHelp` instead.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{App, Arg, AppSettings};
        /// App::new("myprog")
        ///     .setting(AppSettings::SubcommandRequiredElseHelp)
        /// # ;
        /// ```
        SubcommandRequiredElseHelp,
        /// Specifies that this subcommand should be hidden from help messages
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{App, Arg, AppSettings, SubCommand};
        /// App::new("myprog")
        ///     .subcommand(SubCommand::with_name("test")
        ///     .setting(AppSettings::Hidden))
        /// # ;
        /// ```
        Hidden,
        /// Specifies that the final positional argument is a "VarArg" and that `clap` should not
        /// attempt to parse any further args.
        ///
        /// The values of the trailing positional argument will contain all args from itself on.
        ///
        /// **NOTE:** The final positional argument **must** have `.multiple(true)` or the usage string
        /// equivalent.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{App, Arg, AppSettings};
        /// let m = App::new("myprog")
        ///     .setting(AppSettings::TrailingVarArg)
        ///     .arg(Arg::from_usage("<cmd>... 'commands to run'"))
        ///     .get_matches_from(vec!["myprog", "arg1", "-r", "val1"]);
        ///
        /// let trail: Vec<&str> = m.values_of("cmd").unwrap().collect();
        /// assert_eq!(trail, ["arg1", "-r", "val1"]);
        /// ```
        TrailingVarArg,
        /// 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, or an interactive CLI where one
        /// one would not normally type the binary or program name for each command.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{App, Arg, AppSettings};
        /// let m = App::new("myprog")
        ///     .setting(AppSettings::NoBinaryName)
        ///     .arg(Arg::from_usage("<cmd>... 'commands to run'"))
        ///     .get_matches_from(vec!["command", "set"]);
        ///
        /// let cmds: Vec<&str> = m.values_of("cmd").unwrap().collect();
        /// assert_eq!(cmds, ["command", "set"]);
        /// ```
        NoBinaryName,
        /// Specifies that an unexpected argument positional arguments which would otherwise cause a
        /// `ErrorKind::UnknownArgument` error, should instead be treated as a subcommand in the
        /// `ArgMatches` struct.
        ///
        /// **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 treatd as a potential
        /// subcommand. You shoud inform the user appropriatly.
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{App, AppSettings};
        /// // Assume there is an external subcommand named "subcmd"
        /// let m = App::new("myprog")
        ///     .setting(AppSettings::AllowExternalSubcommands)
        ///     .get_matches_from(vec![
        ///         "myprog", "subcmd", "--option", "value", "-fff", "--flag"
        ///     ]);
        ///
        /// // All trailing arguments will be stored under the subcommand's sub-matches using a value
        /// // of the runtime subcommand name (in this case "subcmd")
        /// match m.subcommand() {
        ///     (external, Some(ext_m)) => {
        ///          let ext_args: Vec<&str> = ext_m.values_of(external).unwrap().collect();
        ///          assert_eq!(ext_args, ["--option", "value", "-fff", "--flag"]);
        ///     },
        ///     _ => {},
        /// }
        /// ```
        AllowExternalSubcommands,
        /// Specifies that any invalid UTF-8 code points should be treated as an error and fail
        /// with a `ErrorKind::InvalidUtf8` error.
        ///
        /// **NOTE:** This rule only applies to argument values, as flags, options, and subcommands
        /// themselves only allow valid UTF-8 code points.
        ///
        /// # Platform Specific
        ///
        /// Non Windows systems only
        ///
        /// # Examples
        ///
        /// ```ignore
        /// # use clap::{App, Arg, AppSettings, ErrorKind};
        /// use std::ffi::OsString;
        ///
        /// let m = App::new("myprog")
        ///     .setting(AppSettings::StrictUtf8)
        ///     .arg_from_usage("<arg> 'some positional arg'")
        ///     .get_matches_from_safe(
        ///         vec![
        ///             OsString::from("myprog"),
        ///             OsString::from_vec(vec![0xe9])]);
        ///
        /// assert!(m.is_err());
        /// assert_eq!(m.unwrap_err().kind, ErrorKind::InvalidUtf8);
        /// }
        /// ```
        StrictUtf8,
        /// Specifies that any invalid UTF-8 code points should *not* be treated as an error. This is
        /// the default behavior of `clap`
        ///
        /// **NOTE:** Using argument values with invalid UTF-8 code points requires using Either
        /// `ArgMatches::os_value(s)_of` or `ArgMatches::lossy_value(s)_of` for those particular
        /// arguments which may contain invalid UTF-8 values
        ///
        /// **NOTE:** This rule only applies to  argument values, as flags, options, and subcommands
        /// themselves only allow valid UTF-8 code points.
        ///
        /// # Platform Specific
        ///
        /// Non Windows systems only
        ///
        /// # Examples
        ///
        /// ```ignore
        /// # use clap::{App, Arg, AppSettings};
        /// use std::ffi::OsString;
        /// use std::os::unix::ffi::OsStrExt;
        ///
        /// let r = App::new("myprog")
        ///     .setting(AppSettings::StrictUtf8)
        ///     .arg_from_usage("<arg> 'some positional arg'")
        ///     .get_matches_from_safe(
        ///         vec![
        ///             OsString::from("myprog"),
        ///             OsString::from_vec(vec![0xe9])]);
        ///
        /// assert!(r.is_ok());
        /// let m = r.unwrap();
        /// assert_eq!(m.value_of_os("arg").unwrap().as_bytes(), &[0xe9]);
        /// ```
        AllowInvalidUtf8,
        /// Specifies that leading hyphens are allowed in argument *values*, such as negative numbers
        /// `-10`
        ///
        /// **NOTE:** This can only be set application wide and not on a per argument basis.
        ///
        /// **NOTE:** Use this setting with caution as it silences certain circumstances which would
        /// otherwise be an error (such as accidentally forgetting to specify a value for leading
        /// option)
        ///
        /// # Examples
        ///
        /// ```rust
        /// # use clap::{Arg, App, AppSettings};
        /// // Imagine you needed to represent negative numbers as well, such as -10
        /// let m = App::new("nums")
        ///     .setting(AppSettings::AllowLeadingHyphen)
        ///     .arg(Arg::with_name("neg").index(1))
        ///     .get_matches_from(vec![
        ///         "nums", "-20"
        ///     ]);
        ///
        /// assert_eq!(m.value_of("neg"), Some("-20"));
        /// # ;
        /// ```
        AllowLeadingHyphen,
        /// 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.
        HidePossibleValuesInHelp,
        /// Places the help string for all arguments on the line after the argument
        ///
        /// **NOTE:** This setting is cosmetic only and does not affect any functionality.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{App, Arg, SubCommand, AppSettings};
        /// App::new("myprog")
        ///     .setting(AppSettings::NextLineHelp)
        ///     .get_matches();
        /// ```
        NextLineHelp,
        /// Displays the arguments and subcommands in the help message in the order that they were
        /// declared in, vice alphabetically which is the default.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{App, Arg, SubCommand, AppSettings};
        /// App::new("myprog")
        ///     .setting(AppSettings::DeriveDisplayOrder)
        ///     .get_matches();
        /// ```
        DeriveDisplayOrder,
        /// Uses colorized help messages.
        ///
        /// **NOTE:** Must be compiled with the `color` cargo feature
        ///
        /// # Platform Specific
        ///
        /// This setting only applies to Unix, Linux, and OSX (i.e. non-Windows platforms)
        ///
        /// # Examples
        ///
        /// ```no_run
        /// # use clap::{App, Arg, SubCommand, AppSettings};
        /// App::new("myprog")
        ///     .setting(AppSettings::ColoredHelp)
        ///     .get_matches();
        /// ```
        ColoredHelp,
        #[doc(hidden)]
        NeedsLongVersion,
        #[doc(hidden)]
        NeedsLongHelp,
        #[doc(hidden)]
        NeedsSubcommandHelp,
        #[doc(hidden)]
        DisableVersion,
    }

    impl FromStr for AppSettings {
        type Err = String;
        fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
            match &*s.to_ascii_lowercase() {
                "subcommandsnegatereqs" => Ok(AppSettings::SubcommandsNegateReqs),
                "subcommandsrequired" => Ok(AppSettings::SubcommandRequired),
                "argrequiredelsehelp" => Ok(AppSettings::ArgRequiredElseHelp),
                "globalversion" => Ok(AppSettings::GlobalVersion),
                "versionlesssubcommands" => Ok(AppSettings::VersionlessSubcommands),
                "unifiedhelpmessage" => Ok(AppSettings::UnifiedHelpMessage),
                "waitonerror" => Ok(AppSettings::WaitOnError),
                "subcommandrequiredelsehelp" => Ok(AppSettings::SubcommandRequiredElseHelp),
                "hidden" => Ok(AppSettings::Hidden),
                "allowexternalsubcommands" => Ok(AppSettings::AllowExternalSubcommands),
                "trailingvararg" => Ok(AppSettings::TrailingVarArg),
                "nobinaryname" => Ok(AppSettings::NoBinaryName),
                "strictutf8" => Ok(AppSettings::StrictUtf8),
                "allowinvalidutf8" => Ok(AppSettings::AllowInvalidUtf8),
                "allowleadinghyphen" => Ok(AppSettings::AllowLeadingHyphen),
                "hidepossiblevaluesinhelp" => Ok(AppSettings::HidePossibleValuesInHelp),
                "nextlinehelp" => Ok(AppSettings::NextLineHelp),
                "derivedisplayorder" => Ok(AppSettings::DeriveDisplayOrder),
                "coloredhelp" => Ok(AppSettings::ColoredHelp),
                _ => Err("unknown AppSetting, cannot convert from str".to_owned()),
            }
        }
    }

    #[cfg(test)]
    mod test {
        use super::AppSettings;

        #[test]
        fn app_settings_fromstr() {
            assert_eq!("subcommandsnegatereqs".parse::<AppSettings>().unwrap(), AppSettings::SubcommandsNegateReqs);
            assert_eq!("subcommandsrequired".parse::<AppSettings>().unwrap(), AppSettings::SubcommandRequired);
            assert_eq!("argrequiredelsehelp".parse::<AppSettings>().unwrap(), AppSettings::ArgRequiredElseHelp);
            assert_eq!("globalversion".parse::<AppSettings>().unwrap(), AppSettings::GlobalVersion);
            assert_eq!("versionlesssubcommands".parse::<AppSettings>().unwrap(), AppSettings::VersionlessSubcommands);
            assert_eq!("unifiedhelpmessage".parse::<AppSettings>().unwrap(), AppSettings::UnifiedHelpMessage);
            assert_eq!("waitonerror".parse::<AppSettings>().unwrap(), AppSettings::WaitOnError);
            assert_eq!("subcommandrequiredelsehelp".parse::<AppSettings>().unwrap(), AppSettings::SubcommandRequiredElseHelp);
            assert_eq!("allowexternalsubcommands".parse::<AppSettings>().unwrap(), AppSettings::AllowExternalSubcommands);
            assert_eq!("trailingvararg".parse::<AppSettings>().unwrap(), AppSettings::TrailingVarArg);
            assert_eq!("nobinaryname".parse::<AppSettings>().unwrap(), AppSettings::NoBinaryName);
            assert_eq!("strictutf8".parse::<AppSettings>().unwrap(), AppSettings::StrictUtf8);
            assert_eq!("allowinvalidutf8".parse::<AppSettings>().unwrap(), AppSettings::AllowInvalidUtf8);
            assert_eq!("allowleadinghyphen".parse::<AppSettings>().unwrap(), AppSettings::AllowLeadingHyphen);
            assert_eq!("hidepossiblevaluesinhelp".parse::<AppSettings>().unwrap(), AppSettings::HidePossibleValuesInHelp);
            assert_eq!("coloredhelp".parse::<AppSettings>().unwrap(), AppSettings::ColoredHelp);
            assert_eq!("hidden".parse::<AppSettings>().unwrap(), AppSettings::Hidden);
            assert!("hahahaha".parse::<AppSettings>().is_err());
        }
    }

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