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    use std::collections::{BTreeMap, HashMap, VecDeque};
    use std::slice::Iter;
    use std::io::{self, BufWriter, Write};
    use std::ffi::{OsStr, OsString};
    use std::fmt::Display;
    #[cfg(feature = "debug")]
    use std::os::unix::ffi::OsStrExt;

    use vec_map::{self, VecMap};

    use app::help::Help;
    use app::App;
    use args::{Arg, FlagBuilder, OptBuilder, ArgGroup, PosBuilder};
    use app::settings::{AppSettings, AppFlags};
    use args::{AnyArg, ArgMatcher};
    use args::settings::ArgSettings;
    use errors::{ErrorKind, Error};
    use errors::Result as ClapResult;
    use INVALID_UTF8;
    use suggestions;
    use INTERNAL_ERROR_MSG;
    use SubCommand;
    use fmt::Format;
    use osstringext::OsStrExt2;
    use app::meta::AppMeta;
    use args::MatchedArg;

    #[allow(missing_debug_implementations)]
    #[doc(hidden)]
    pub struct Parser<'a, 'b> where 'a: 'b {
        required: Vec<&'b str>,
        short_list: Vec<char>,
        long_list: Vec<&'b str>,
        blacklist: Vec<&'b str>,
        // A list of possible flags
        flags: Vec<FlagBuilder<'a, 'b>>,
        // A list of possible options
        opts: Vec<OptBuilder<'a, 'b>>,
        // A list of positional arguments
        positionals: VecMap<PosBuilder<'a, 'b>>,
        // A list of subcommands
        #[doc(hidden)]
        pub subcommands: Vec<App<'a, 'b>>,
        groups: HashMap<&'a str, ArgGroup<'a>>,
        global_args: Vec<Arg<'a, 'b>>,
        overrides: Vec<&'b str>,
        help_short: Option<char>,
        version_short: Option<char>,
        settings: AppFlags,
        pub meta: AppMeta<'b>,
    }

    impl<'a, 'b> Default for Parser<'a, 'b> {
        fn default() -> Self {
            Parser {
                flags: vec![],
                opts: vec![],
                positionals: VecMap::new(),
                subcommands: vec![],
                help_short: None,
                version_short: None,
                required: vec![],
                short_list: vec![],
                long_list: vec![],
                blacklist: vec![],
                groups: HashMap::new(),
                global_args: vec![],
                overrides: vec![],
                settings: AppFlags::new(),
                meta: AppMeta::new(),
            }
        }
    }

    macro_rules! parse_positional {
        ($_self:ident, $p:ident, $arg_os:ident, $pos_only:ident, $pos_counter:ident, $matcher:ident) => {
            debugln!("macro=parse_positional!;");
            validate_multiples!($_self, $p, $matcher);

            if let Err(e) = $_self.add_val_to_arg($p, &$arg_os, $matcher) {
                return Err(e);
            }
            if !$pos_only &&
               ($_self.settings.is_set(AppSettings::TrailingVarArg) &&
                $pos_counter == $_self.positionals.len()) {
                $pos_only = true;
            }

            $matcher.inc_occurrence_of($p.name);
            let _ = $_self.groups_for_arg($p.name).and_then(|vec| Some($matcher.inc_occurrences_of(&*vec)));
            arg_post_processing!($_self, $p, $matcher);
            // Only increment the positional counter if it doesn't allow multiples
            if !$p.settings.is_set(ArgSettings::Multiple) {
                $pos_counter += 1;
            }
        };
    }

    impl<'a, 'b> Parser<'a, 'b> where 'a: 'b {
        pub fn with_name(n: String) -> Self {
            Parser { meta: AppMeta::with_name(n), ..Default::default() }
        }

        pub fn help_short(&mut self, s: &str) {
            self.help_short = s.trim_left_matches(|c| c == '-')
                               .chars()
                               .nth(0);
        }

        pub fn version_short(&mut self, s: &str) {
            self.version_short = s.trim_left_matches(|c| c == '-')
                                  .chars()
                                  .nth(0);
        }

        // actually adds the arguments
        pub fn add_arg(&mut self, a: &Arg<'a, 'b>) {
            debug_assert!(!(self.flags.iter().any(|f| &f.name == &a.name)
                || self.opts.iter().any(|o| o.name == a.name)
                || self.positionals.values().any(|p| p.name == a.name)),
                format!("Non-unique argument name: {} is already in use", a.name));
            if let Some(grp) = a.group {
                let ag = self.groups.entry(grp).or_insert_with(|| ArgGroup::with_name(grp));
                ag.args.push(a.name);
            }
            if let Some(s) = a.short {
                debug_assert!(!self.short_list.contains(&s),
                    format!("Argument short must be unique\n\n\t-{} is already in use", s));
                self.short_list.push(s);
            }
            if let Some(l) = a.long {
                debug_assert!(!self.long_list.contains(&l),
                    format!("Argument long must be unique\n\n\t--{} is already in use", l));
                self.long_list.push(l);
                if l == "help" {
                    self.set(AppSettings::NeedsLongHelp);
                } else if l == "version" {
                    self.set(AppSettings::NeedsLongVersion);
                }
            }
            if a.is_set(ArgSettings::Required) {
                self.required.push(a.name);
            }
            if a.index.is_some() || (a.short.is_none() && a.long.is_none()) {
                let i = if a.index.is_none() {
                    (self.positionals.len() + 1)
                } else {
                    a.index.unwrap() as usize
                };
                debug_assert!(!self.positionals.contains_key(i),
                    format!("Argument \"{}\" has the same index as another positional \
                        argument\n\n\tPerhaps try .multiple(true) to allow one positional argument \
                        to take multiple values", a.name));
                let pb = PosBuilder::from_arg(&a, i as u64, &mut self.required);
                self.positionals.insert(i, pb);
            } else if a.is_set(ArgSettings::TakesValue) {
                let mut ob = OptBuilder::from_arg(&a, &mut self.required);
                if self.settings.is_set(AppSettings::DeriveDisplayOrder) && a.disp_ord == 999 {
                    ob.disp_ord = if self.settings.is_set(AppSettings::UnifiedHelpMessage) {
                        self.flags.len() + self.opts.len()
                    } else {
                        self.opts.len()
                    };
                }
                self.opts.push(ob);
            } else {
                let mut fb = FlagBuilder::from(a);
                if self.settings.is_set(AppSettings::DeriveDisplayOrder) && a.disp_ord == 999 {
                    fb.disp_ord = if self.settings.is_set(AppSettings::UnifiedHelpMessage) {
                        self.flags.len() + self.opts.len()
                    } else {
                        self.flags.len()
                    };
                }
                self.flags.push(fb);
            }
            if a.is_set(ArgSettings::Global) {
                debug_assert!(!a.is_set(ArgSettings::Required),
                    format!("Global arguments cannot be required.\n\n\t'{}' is marked as global and \
                            required", a.name));
                self.global_args.push(a.into());
            }
        }

        pub fn add_group(&mut self, group: ArgGroup<'a>) {
            if group.required {
                self.required.push(group.name.into());
                if let Some(ref reqs) = group.requires {
                    self.required.extend_from_slice(reqs);
                }
                if let Some(ref bl) = group.conflicts {
                    self.blacklist.extend_from_slice(bl);
                }
            }
            let mut found = false;
            if let Some(ref mut grp) = self.groups.get_mut(&group.name) {
                grp.args.extend_from_slice(&group.args);
                grp.requires = group.requires.clone();
                grp.conflicts = group.conflicts.clone();
                grp.required = group.required;
                found = true;
            }
            if !found {
                self.groups.insert(group.name.into(), group);
            }
        }

        pub fn add_subcommand(&mut self, mut subcmd: App<'a, 'b>) {
            debugln!("fn=Parser::add_subcommand;");
            debug!("Is help...");
            if subcmd.p.meta.name == "help" {
                sdebugln!("Yes");
                self.settings.set(AppSettings::NeedsSubcommandHelp);
            } else { sdebugln!("No"); }
            debug!("Using Setting VersionlessSubcommands...");
            if self.settings.is_set(AppSettings::VersionlessSubcommands) {
                sdebugln!("Yes");
                subcmd.p.settings.set(AppSettings::DisableVersion);
            } else { sdebugln!("No"); }
            debug!("Using Setting GlobalVersion...");
            if self.settings.is_set(AppSettings::GlobalVersion) && subcmd.p.meta.version.is_none() &&
               self.meta.version.is_some() {
                sdebugln!("Yes");
                subcmd = subcmd.setting(AppSettings::GlobalVersion)
                               .version(self.meta.version.unwrap());
            } else { sdebugln!("No"); }
            if self.settings.is_set(AppSettings::DeriveDisplayOrder) {
                subcmd.p.meta.disp_ord = self.subcommands.len();
            }
            self.subcommands.push(subcmd);
        }

        pub fn required(&self) -> Iter<&str> {
            self.required.iter()
        }

        #[cfg_attr(feature = "lints", allow(for_kv_map))]
        pub fn get_required_from(&self,
                             reqs: &[&'a str],
                             matcher: Option<&ArgMatcher<'a>>)
                             -> VecDeque<String> {
            let mut c_flags: Vec<&str> = vec![];
            let mut c_pos: Vec<&str> = vec![];
            let mut c_opt: Vec<&str> = vec![];
            let mut grps: Vec<&str> = vec![];
            for name in reqs {
                if self.flags.iter().any(|f| &f.name == name) {
                    c_flags.push(name);
                } else if self.opts.iter().any(|o| &o.name == name) {
                    c_opt.push(name);
                } else if self.groups.contains_key(name) {
                    grps.push(name);
                } else {
                    c_pos.push(name);
                }
            }
            macro_rules! fill_vecs {
                ($_self:ident {
                    $t1:ident => $v1:ident => $i1:ident,
                    $t2:ident => $v2:ident => $i2:ident,
                    $t3:ident => $v3:ident => $i3:ident,
                    $gv:ident, $tmp:ident
                }) => {
                    for a in &$v1 {
                        if let Some(a) = self.$t1.$i1().filter(|arg| &arg.name == a).next() {
                            if let Some(ref rl) = a.requires {
                                for r in rl {
                                    if !reqs.contains(r) {
                                        if $_self.$t1.$i1().any(|t| &t.name == r) {
                                            $tmp.push(*r);
                                        } else if $_self.$t2.$i2().any(|t| &t.name == r) {
                                            $v2.push(r);
                                        } else if $_self.$t3.$i3().any(|t| &t.name == r) {
                                            $v3.push(r);
                                        } else if $_self.groups.contains_key(r) {
                                            $gv.push(r);
                                        }
                                    }
                                }
                            }
                        }
                    }
                    $v1.extend(&$tmp);
                };
            }

            let mut tmp = vec![];
            fill_vecs!(self {
                flags       => c_flags => iter,
                opts        => c_opt   => iter,
                positionals => c_pos   => values,
                grps, tmp
            });
            tmp.clear();
            fill_vecs!(self {
                opts        => c_opt   => iter,
                flags       => c_flags => iter,
                positionals => c_pos   => values,
                grps, tmp
            });
            tmp.clear();
            fill_vecs!(self {
                positionals => c_pos   => values,
                opts        => c_opt   => iter,
                flags       => c_flags => iter,
                grps, tmp
            });
            let mut ret_val = VecDeque::new();

            let mut pmap = BTreeMap::new();
            for p in c_pos.into_iter() {
                if matcher.is_some() && matcher.as_ref().unwrap().contains(p) {
                    continue;
                }
                if let Some(p) = self.positionals.values().filter(|x| &x.name == &p).next() {
                    pmap.insert(p.index, p.to_string());
                }
            }
            for (_, s) in pmap {
                ret_val.push_back(s);
            }
            macro_rules! write_arg {
                ($i:expr, $m:ident, $v:ident, $r:ident) => {
                    for f in $v.into_iter() {
                        if $m.is_some() && $m.as_ref().unwrap().contains(f) {
                            continue;
                        }
                        $r.push_back($i.filter(|flg| &flg.name == &f).next().unwrap().to_string());
                    }
                }
            }
            write_arg!(self.flags.iter(), matcher, c_flags, ret_val);
            write_arg!(self.opts.iter(), matcher, c_opt, ret_val);
            for g in grps.into_iter() {
                let g_string = self.args_in_group(g)
                                   .join("|");
                ret_val.push_back(format!("[{}]", &g_string[..g_string.len()]));
            }

            ret_val
        }

        pub fn has_flags(&self) -> bool {
            !self.flags.is_empty()
        }

        pub fn has_opts(&self) -> bool {
            !self.opts.is_empty()
        }

        pub fn has_positionals(&self) -> bool {
            !self.positionals.is_empty()
        }

        pub fn has_subcommands(&self) -> bool {
            !self.subcommands.is_empty()
        }

        pub fn is_set(&self, s: AppSettings) -> bool {
            self.settings.is_set(s)
        }

        pub fn set(&mut self, s: AppSettings) {
            self.settings.set(s)
        }

        pub fn verify_positionals(&mut self) {
            // Because you must wait until all arguments have been supplied, this is the first chance
            // to make assertions on positional argument indexes
            //
            // Firt we verify that the index highest supplied index, is equal to the number of
            // positional arguments to verify there are no gaps (i.e. supplying an index of 1 and 3
            // but no 2)
            if let Some((idx, ref p)) = self.positionals.iter().rev().next() {
                assert!(!(idx != self.positionals.len()),
                    format!("Found positional argument \"{}\" who's index is {} but there are only {} \
                        positional arguments defined", p.name, idx, self.positionals.len()));
            }

            // Next we verify that only the highest index has a .multiple(true) (if any)
            assert!(!self.positionals.values()
                         .any(|a|
                             a.settings.is_set(ArgSettings::Multiple) &&
                             (a.index as usize != self.positionals.len())
                         ),
                    "Only the positional argument with the highest index may accept multiple values");

            // If it's required we also need to ensure all previous positionals are
            // required too
            let mut found = false;
            for p in self.positionals.values().rev() {
                if found {
                    debug_assert!(p.settings.is_set(ArgSettings::Required),
                        "Found positional argument which is not required with a lower index than a \
                        required positional argument: {:?} index {}",
                        p.name,
                        p.index);
                } else if p.settings.is_set(ArgSettings::Required) {
                    found = true;
                    continue;
                }
            }
        }

        pub fn propogate_globals(&mut self) {
            for sc in &mut self.subcommands {
                // We have to create a new scope in order to tell rustc the borrow of `sc` is
                // done and to recursively call this method
                {
                    for a in &self.global_args {
                        sc.p.add_arg(a);
                    }
                }
                sc.p.propogate_globals();
            }
        }

        // The actual parsing function
        #[cfg_attr(feature = "lints", allow(while_let_on_iterator))]
        pub fn get_matches_with<I, T>(&mut self,
                                  matcher: &mut ArgMatcher<'a>,
                                  it: &mut I)
                                  -> ClapResult<()>
            where I: Iterator<Item = T>,
                  T: Into<OsString>
        {
            debugln!("fn=get_matches_with;");
            // First we create the `--help` and `--version` arguments and add them if
            // necessary
            self.create_help_and_version();

            let mut pos_only = false;
            let mut subcmd_name: Option<String> = None;
            let mut needs_val_of: Option<&str> = None;
            let mut pos_counter = 1;
            while let Some(arg) = it.next() {
                let arg_os = arg.into();
                debugln!("Begin parsing '{:?}' ({:?})", arg_os, &*arg_os.as_bytes());

                // Is this a new argument, or values from a previous option?
                debug!("Starts new arg...");
                let starts_new_arg = if arg_os.starts_with(b"-") {
                    sdebugln!("Yes");
                    !(arg_os.len_() == 1)
                } else {
                    sdebugln!("No");
                    false
                };

                // Has the user already passed '--'?
                if !pos_only {
                    let pos_sc = self.subcommands.iter().any(|s| &s.p.meta.name[..] == &*arg_os);
                    if (!starts_new_arg || self.is_set(AppSettings::AllowLeadingHyphen)) && !pos_sc {
                        // Check to see if parsing a value from an option
                        if let Some(nvo) = needs_val_of {
                            // get the OptBuilder so we can check the settings
                            if let Some(opt) = self.opts.iter().filter(|o| &o.name == &nvo).next() {
                                needs_val_of = try!(self.add_val_to_arg(opt, &arg_os, matcher));
                                // get the next value from the iterator
                                continue;
                            }
                        }
                    }
                    if arg_os.starts_with(b"--") {
                        if arg_os.len_() == 2 {
                            // The user has passed '--' which means only positional args follow no matter
                            // what they start with
                            pos_only = true;
                            continue;
                        }

                        needs_val_of = try!(self.parse_long_arg(matcher, &arg_os));
                        continue;
                    } else if arg_os.starts_with(b"-") && arg_os.len_() != 1 {
                        needs_val_of = try!(self.parse_short_arg(matcher, &arg_os));
                        if !(needs_val_of.is_none() && self.is_set(AppSettings::AllowLeadingHyphen)) {
                            continue;
                        }
                    }

                    if pos_sc {
                        if &*arg_os == "help" &&
                           self.settings.is_set(AppSettings::NeedsSubcommandHelp) {
                            let cmds: Vec<OsString> = it.map(|c| c.into()).collect();
                            let mut sc = {
                                let mut sc: &Parser = self;
                                for (i, cmd) in cmds.iter().enumerate() {
                                    if let Some(c) = sc.subcommands.iter().filter(|s| &*s.p.meta.name == cmd).next().map(|sc| &sc.p) {
                                        sc = c;
                                        if i == cmds.len() - 1 {
                                            break;
                                        }
                                    } else {
                                        return Err(
                                            Error::unrecognized_subcommand(
                                                cmd.to_string_lossy().into_owned(),
                                                self.meta.bin_name.as_ref().unwrap_or(&self.meta.name)));
                                    }
                                }
                                sc.clone()
                            };
                            sc.create_help_and_version();
                            return sc._help();
                        }
                        subcmd_name = Some(arg_os.to_str().expect(INVALID_UTF8).to_owned());
                        break;
                    } else if let Some(candidate) = suggestions::did_you_mean(
                                                            &*arg_os.to_string_lossy(),
                                                            self.subcommands.iter().map(|s| &s.p.meta.name)) {
                        return Err(
                            Error::invalid_subcommand(arg_os.to_string_lossy().into_owned(),
                                                    candidate,
                                                    self.meta.bin_name.as_ref().unwrap_or(&self.meta.name),
                                                    &*self.create_current_usage(matcher)));
                    }
                }

                if let Some(p) = self.positionals.get(pos_counter) {
                    parse_positional!(self, p, arg_os, pos_only, pos_counter, matcher);
                } else {
                    if self.settings.is_set(AppSettings::AllowExternalSubcommands) {
                        let mut sc_m = ArgMatcher::new();
                        while let Some(v) = it.next() {
                            let a = v.into();
                            if let None = a.to_str() {
                                if !self.settings.is_set(AppSettings::StrictUtf8)  {
                                    return Err(
                                        Error::invalid_utf8(&*self.create_current_usage(matcher))
                                    );
                                }
                            }
                            sc_m.add_val_to("EXTERNAL_SUBCOMMAND", &a);
                        }

                        matcher.subcommand(SubCommand {
                            name: "EXTERNAL_SUBCOMMAND".into(),
                            matches: sc_m.into(),
                        });
                    } else {
                        return Err(Error::unknown_argument(
                            &*arg_os.to_string_lossy(),
                            "",
                            &*self.create_current_usage(matcher)));
                    }
                }
            }

            let mut reqs_validated = false;
            if let Some(a) = needs_val_of {
                if let Some(o) = self.opts.iter().filter(|o| &o.name == &a).next() {
                    try!(self.validate_required(matcher));
                    reqs_validated = true;
                    let should_err = if let Some(ref v) = matcher.0.args.get(&*o.name) {
                        v.vals.is_empty() && !(o.min_vals.is_some() && o.min_vals.unwrap() == 0)
                    } else {
                        true
                    };
                    if should_err {
                        return Err(Error::empty_value(o, &*self.create_current_usage(matcher)));
                    }
                } else {
                    return Err(Error::empty_value(self.positionals
                                                       .values()
                                                       .filter(|p| &p.name == &a)
                                                       .next()
                                                       .expect(INTERNAL_ERROR_MSG),
                                                    &*self.create_current_usage(matcher)));
                }
            }

            try!(self.add_defaults(matcher));
            try!(self.validate_blacklist(matcher));
            try!(self.validate_num_args(matcher));
            matcher.usage(self.create_usage(&[]));

            if !(self.settings.is_set(AppSettings::SubcommandsNegateReqs) && subcmd_name.is_some()) &&
                !reqs_validated {
                try!(self.validate_required(matcher));
            }
            if let Some(sc_name) = subcmd_name {
                try!(self.parse_subcommand(sc_name, matcher, it));
            } else if self.is_set(AppSettings::SubcommandRequired) {
                let bn = self.meta.bin_name.as_ref().unwrap_or(&self.meta.name);
                return Err(Error::missing_subcommand(bn, &self.create_current_usage(matcher)));
            } else if self.is_set(AppSettings::SubcommandRequiredElseHelp) {
                let mut out = vec![];
                try!(self.write_help(&mut out));
                return Err(Error {
                    message: String::from_utf8_lossy(&*out).into_owned(),
                    kind: ErrorKind::MissingArgumentOrSubcommand,
                    info: None,
                });
            }
            if matcher.is_empty() && matcher.subcommand_name().is_none() &&
               self.is_set(AppSettings::ArgRequiredElseHelp) {
                let mut out = vec![];
                try!(self.write_help(&mut out));
                return Err(Error {
                    message: String::from_utf8_lossy(&*out).into_owned(),
                    kind: ErrorKind::MissingArgumentOrSubcommand,
                    info: None,
                });
            }
            Ok(())
        }

        fn parse_subcommand<I, T>(&mut self, sc_name: String, matcher: &mut ArgMatcher<'a>, it: &mut I) -> ClapResult<()>
            where I: Iterator<Item = T>,
                  T: Into<OsString>
        {
            use std::fmt::Write;
            debugln!("fn=parse_subcommand;");
            let mut mid_string = String::new();
            if !self.settings.is_set(AppSettings::SubcommandsNegateReqs) {
                let mut hs: Vec<&str> = self.required.iter().map(|n| &**n).collect();
                for k in matcher.arg_names() {
                    hs.push(k);
                }
                let reqs = self.get_required_from(&hs, Some(matcher));

                for s in &reqs {
                    write!(&mut mid_string, " {}", s).expect(INTERNAL_ERROR_MSG);
                }
            }
            mid_string.push_str(" ");
            if let Some(ref mut sc) = self.subcommands
                                          .iter_mut()
                                          .filter(|s| &s.p.meta.name == &sc_name)
                                          .next() {
                let mut sc_matcher = ArgMatcher::new();
                // bin_name should be parent's bin_name + [<reqs>] + the sc's name separated by
                // a space
                sc.p.meta.usage = Some(format!("{}{}{}",
                                        self.meta.bin_name.as_ref().unwrap_or(&String::new()),
                                        if self.meta.bin_name.is_some() {
                                            &*mid_string
                                        } else {
                                            ""
                                        },
                                        &*sc.p.meta.name));
                sc.p.meta.bin_name = Some(format!("{}{}{}",
                                           self.meta.bin_name.as_ref().unwrap_or(&String::new()),
                                           if self.meta.bin_name.is_some() {
                                               " "
                                           } else {
                                               ""
                                           },
                                           &*sc.p.meta.name));
                try!(sc.p.get_matches_with(&mut sc_matcher, it));
                matcher.subcommand(SubCommand {
                    name: sc.p.meta.name.clone(),
                    matches: sc_matcher.into(),
                });
            }
            Ok(())
        }

        fn blacklisted_from(&self, name: &str, matcher: &ArgMatcher) -> Option<String> {
            for k in matcher.arg_names() {
                if let Some(f) = self.flags.iter().filter(|f| &f.name == &k).next() {
                    if let Some(ref bl) = f.blacklist {
                        if bl.contains(&name) {
                            return Some(f.to_string());
                        }
                    }
                }
                if let Some(o) = self.opts.iter().filter(|o| &o.name == &k).next() {
                    if let Some(ref bl) = o.blacklist {
                        if bl.contains(&name) {
                            return Some(o.to_string());
                        }
                    }
                }
                if let Some(pos) = self.positionals.values().filter(|p| &p.name == &k).next() {
                    if let Some(ref bl) = pos.blacklist {
                        if bl.contains(&name) {
                            return Some(pos.to_string());
                        }
                    }
                }
            }
            None
        }

        fn overriden_from(&self, name: &str, matcher: &ArgMatcher) -> Option<&'a str> {
            for k in matcher.arg_names() {
                if let Some(f) = self.flags.iter().filter(|f| &f.name == &k).next() {
                    if let Some(ref bl) = f.overrides {
                        if bl.contains(&name.into()) {
                            return Some(f.name);
                        }
                    }
                }
                if let Some(o) = self.opts.iter().filter(|o| &o.name == &k).next() {
                    if let Some(ref bl) = o.overrides {
                        if bl.contains(&name.into()) {
                            return Some(o.name);
                        }
                    }
                }
                if let Some(pos) = self.positionals.values().filter(|p| &p.name == &k).next() {
                    if let Some(ref bl) = pos.overrides {
                        if bl.contains(&name.into()) {
                            return Some(pos.name);
                        }
                    }
                }
            }
            None
        }

        fn groups_for_arg(&self, name: &str) -> Option<Vec<&'a str>> {
            debugln!("fn=groups_for_arg;");

            if self.groups.is_empty() {
                debugln!("No groups defined");
                return None;
            }
            let mut res = vec![];
            debugln!("Searching through groups...");
            for (gn, grp) in &self.groups {
                for a in &grp.args {
                    if a == &name {
                        sdebugln!("\tFound '{}'", gn);
                        res.push(*gn);
                    }
                }
            }
            if res.is_empty() {
                return None;
            }

            Some(res)
        }

        fn args_in_group(&self, group: &str) -> Vec<String> {
            let mut g_vec = vec![];
            let mut args = vec![];

            for n in &self.groups.get(group).unwrap().args {
                if let Some(f) = self.flags.iter().filter(|f| &f.name == n).next() {
                    args.push(f.to_string());
                } else if let Some(f) = self.opts.iter().filter(|o| &o.name == n).next() {
                    args.push(f.to_string());
                } else if self.groups.contains_key(&**n) {
                    g_vec.push(*n);
                } else if let Some(p) = self.positionals
                                         .values()
                                         .filter(|p| &p.name == n)
                                         .next() {
                    args.push(p.to_string());
                }
            }

            for av in g_vec.iter().map(|g| self.args_in_group(g)) {
                args.extend(av);
            }
            args.dedup();
            args.iter().map(ToOwned::to_owned).collect()
        }

        fn arg_names_in_group(&self, group: &str) -> Vec<&'a str> {
            let mut g_vec = vec![];
            let mut args = vec![];

            for n in &self.groups.get(group).unwrap().args {
                if self.groups.contains_key(&*n) {
                    g_vec.push(*n);
                } else {
                    args.push(*n);
                }
            }

            for av in g_vec.iter().map(|g| self.arg_names_in_group(g)) {
                args.extend(av);
            }
            args.dedup();
            args.iter().map(|s| *s).collect()
        }

        fn create_help_and_version(&mut self) {
            debugln!("fn=create_help_and_version;");
            // name is "hclap_help" because flags are sorted by name
            if !self.flags.iter().any(|a| a.long.is_some() && a.long.unwrap() == "help") {
                debugln!("Building --help");
                if self.help_short.is_none() && !self.short_list.contains(&'h') {
                    self.help_short = Some('h');
                }
                let arg = FlagBuilder {
                    name: "hclap_help",
                    short: self.help_short,
                    long: Some("help"),
                    help: Some("Prints help information"),
                    ..Default::default()
                };
                self.long_list.push("help");
                self.flags.push(arg);
            }
            if !self.settings.is_set(AppSettings::DisableVersion) &&
               !self.flags.iter().any(|a| a.long.is_some() && a.long.unwrap() == "version") {
                debugln!("Building --version");
                if self.version_short.is_none() && !self.short_list.contains(&'V') {
                    self.version_short = Some('V');
                }
                // name is "vclap_version" because flags are sorted by name
                let arg = FlagBuilder {
                    name: "vclap_version",
                    short: self.version_short,
                    long: Some("version"),
                    help: Some("Prints version information"),
                    ..Default::default()
                };
                self.long_list.push("version");
                self.flags.push(arg);
            }
            if !self.subcommands.is_empty() &&
               !self.subcommands
                    .iter()
                    .any(|s| &s.p.meta.name[..] == "help") {
                debugln!("Building help");
                self.subcommands.push(App::new("help").about("Prints this message or the help message of the given subcommand(s)"));
            }
        }

        // Retrieves the names of all args the user has supplied thus far, except required ones
        // because those will be listed in self.required
        pub fn create_current_usage(&self, matcher: &'b ArgMatcher<'a>) -> String {
            self.create_usage(
                &*matcher.arg_names()
                       .iter()
                       .filter(|n| {
                            if let Some(o) = self.opts
                                                 .iter()
                                                 .filter(|&o| &&o.name == n)
                                                 .next() {
                                !o.settings.is_set(ArgSettings::Required)
                            } else if let Some(p) = self.positionals
                                                        .values()
                                                        .filter(|&p| &&p.name == n)
                                                        .next() {
                                !p.settings.is_set(ArgSettings::Required)
                            } else {
                                true // flags can't be required, so they're always true
                            }})
                        .map(|&n| n)
                        .collect::<Vec<_>>())
        }

        fn check_for_help_and_version_str(&self, arg: &OsStr) -> ClapResult<()> {
            debug!("Checking if --{} is help or version...", arg.to_str().unwrap());
            if arg == "help" && self.settings.is_set(AppSettings::NeedsLongHelp) {
                sdebugln!("Help");
                try!(self._help());
            }
            if arg == "version" && self.settings.is_set(AppSettings::NeedsLongVersion) {
                sdebugln!("Version");
                try!(self._version());
            }
            sdebugln!("Neither");

            Ok(())
        }

        fn check_for_help_and_version_char(&self, arg: char) -> ClapResult<()> {
            debug!("Checking if -{} is help or version...", arg);
            if let Some(h) = self.help_short {
                sdebugln!("Help");
                if arg == h { try!(self._help()); }
            }
            if let Some(v) = self.version_short {
                sdebugln!("Help");
                if arg == v { try!(self._version()); }
            }
            sdebugln!("Neither");
            Ok(())
        }

        fn _help(&self) -> ClapResult<()> {
            try!(self.print_help());
            Err(Error {
                message: String::new(),
                kind: ErrorKind::HelpDisplayed,
                info: None,
            })
        }

        fn _version(&self) -> ClapResult<()> {
            let out = io::stdout();
            let mut buf_w = BufWriter::new(out.lock());
            try!(self.print_version(&mut buf_w));
            Err(Error {
                message: String::new(),
                kind: ErrorKind::VersionDisplayed,
                info: None,
            })
        }

        fn parse_long_arg(&mut self,
                          matcher: &mut ArgMatcher<'a>,
                          full_arg: &OsStr)
                          -> ClapResult<Option<&'b str>> { // maybe here lifetime should be 'a
            debugln!("fn=parse_long_arg;");
            let mut val = None;
            debug!("Does it contain '='...");
            let arg = if full_arg.contains_byte(b'=') {
                let (p0, p1) = full_arg.trim_left_matches(b'-').split_at_byte(b'=');
                sdebugln!("Yes '{:?}'", p1);
                val = Some(p1);
                p0
            } else {
                sdebugln!("No");
                full_arg.trim_left_matches(b'-')
            };

            if let Some(opt) = self.opts
                        .iter()
                        .filter(|v| v.long.is_some() && &*v.long.unwrap() == arg)
                        .next() {
                debugln!("Found valid opt '{}'", opt.to_string());
                let ret = try!(self.parse_opt(val, opt, matcher));
                arg_post_processing!(self, opt, matcher);

                return Ok(ret);
            } else if let Some(flag) = self.flags
                        .iter()
                        .filter(|v| v.long.is_some() && &*v.long.unwrap() == arg)
                        .next() {
                debugln!("Found valid flag '{}'", flag.to_string());
                // Only flags could be help or version, and we need to check the raw long
                // so this is the first point to check
                try!(self.check_for_help_and_version_str(&arg));

                try!(self.parse_flag(flag, matcher));

                // Handle conflicts, requirements, etc.
                arg_post_processing!(self, flag, matcher);

                return Ok(None);
            }

            debugln!("Didn't match anything");
            self.did_you_mean_error(arg.to_str().expect(INVALID_UTF8), matcher).map(|_| None)
        }

        fn parse_short_arg(&mut self,
                           matcher: &mut ArgMatcher<'a>,
                           full_arg: &OsStr)
                           -> ClapResult<Option<&'a str>> {
            debugln!("fn=parse_short_arg;");
            // let mut utf8 = true;
            let arg_os = full_arg.trim_left_matches(b'-');
            let arg = arg_os.to_string_lossy();

            for c in arg.chars() {
                // Check for matching short options, and return the name if there is no trailing
                // concatenated value: -oval
                // Option: -o
                // Value: val
                if let Some(opt) = self.opts
                            .iter()
                            .filter(|&v| v.short.is_some() && v.short.unwrap() == c)
                            .next() {
                    debugln!("Found valid short opt -{} in '{}'", c, arg);
                    // Check for trailing concatenated value
                    let p: Vec<_> = arg.splitn(2, c).collect();
                    debugln!("arg: {:?}, arg_os: {:?}, full_arg: {:?}", arg, arg_os, full_arg);
                    debugln!("p[0]: {:?}, p[1]: {:?}", p[0].as_bytes(), p[1].as_bytes());
                    let i = p[0].as_bytes().len() + 1;
                    let val = if p[1].as_bytes().len() > 0 {
                        debugln!("setting val: {:?} (bytes), {:?} (ascii)", arg_os.split_at(i).1.as_bytes(), arg_os.split_at(i).1);
                        Some(arg_os.split_at(i).1)
                    } else {
                        None
                    };

                    // Default to "we're expecting a value later"
                    let ret = try!(self.parse_opt(val, opt, matcher));

                    arg_post_processing!(self, opt, matcher);

                    return Ok(ret);
                } else if let Some(flag) = self.flags.iter().filter(|&v| v.short.is_some() && v.short.unwrap() == c).next() {
                    debugln!("Found valid short flag -{}", c);
                    // Only flags can be help or version
                    try!(self.check_for_help_and_version_char(c));
                    try!(self.parse_flag(flag, matcher));
                    // Handle conflicts, requirements, overrides, etc.
                    // Must be called here due to mutablilty
                    arg_post_processing!(self, flag, matcher);
                } else if !self.is_set(AppSettings::AllowLeadingHyphen) {
                    let mut arg = String::new();
                    arg.push('-');
                    arg.push(c);
                    return Err(
                        Error::unknown_argument(&*arg, "", &*self.create_current_usage(matcher)));
                }
            }
            Ok(None)
        }

        fn parse_opt(&self,
                     val: Option<&OsStr>,
                     opt: &OptBuilder<'a, 'b>,
                     matcher: &mut ArgMatcher<'a>)
                     -> ClapResult<Option<&'a str>> {
            debugln!("fn=parse_opt;");
            validate_multiples!(self, opt, matcher);

            debug!("Checking for val...");
            if let Some(fv) = val {
                let v = fv.trim_left_matches(b'=');
                if !opt.is_set(ArgSettings::EmptyValues) && v.len_() == 0 {
                    sdebugln!("Found Empty - Error");
                    return Err(Error::empty_value(opt, &*self.create_current_usage(matcher)));
                }
                sdebugln!("Found - {:?}, len: {}", v, v.len_());
                try!(self.add_val_to_arg(opt, v, matcher));
            } else { sdebugln!("None"); }

            matcher.inc_occurrence_of(opt.name);
            // Increment or create the group "args"
            self.groups_for_arg(opt.name).and_then(|vec| Some(matcher.inc_occurrences_of(&*vec)));

            if val.is_none() || (opt.is_set(ArgSettings::Multiple) && matcher.needs_more_vals(opt)) {
                return Ok(Some(opt.name));
            }
            Ok(None)
        }

        fn add_val_to_arg<A>(&self,
                            arg: &A,
                            val: &OsStr,
                            matcher: &mut ArgMatcher<'a>)
                            -> ClapResult<Option<&'a str>>
            where A: AnyArg<'a, 'b> + Display {
            debugln!("fn=add_val_to_arg;");
            let mut ret = None;
            if let Some(delim) = arg.val_delim() {
                if val.is_empty_() {
                    ret = try!(self.add_single_val_to_arg(arg, val, matcher));
                } else {
                    for v in val.split(delim as u32 as u8) {
                        ret = try!(self.add_single_val_to_arg(arg, v, matcher));
                    }
                }
            } else {
                ret = try!(self.add_single_val_to_arg(arg, val, matcher));
            }
            Ok(ret)
        }

        fn add_single_val_to_arg<A>(&self, arg: &A, v: &OsStr, matcher: &mut ArgMatcher<'a>) -> ClapResult<Option<&'a str>>
            where A: AnyArg<'a, 'b> + Display
        {
            debugln!("adding val: {:?}", v);
            matcher.add_val_to(arg.name(), v);

            // Increment or create the group "args"
            if let Some(grps) = self.groups_for_arg(arg.name()) {
                for grp in grps {
                    matcher.add_val_to(&*grp, v);
                }
            }

            // The validation must come AFTER inserting into 'matcher' or the usage string
            // can't be built
            self.validate_value(arg, v, matcher)
        }

        fn validate_value<A>(&self, arg: &A, val: &OsStr, matcher: &ArgMatcher<'a>) -> ClapResult<Option<&'a str>>
            where A: AnyArg<'a, 'b> + Display {
            debugln!("fn=validate_value; val={:?}", val);
            if self.is_set(AppSettings::StrictUtf8) && val.to_str().is_none() {
                return Err(Error::invalid_utf8(&*self.create_current_usage(matcher)));
            }
            if let Some(ref p_vals) = arg.possible_vals() {
                let val_str = val.to_string_lossy();
                if !p_vals.contains(&&*val_str) {
                    return Err(
                        Error::invalid_value(val_str,
                                            p_vals,
                                            arg,
                                            &*self.create_current_usage(matcher)));
                }
            }
            if !arg.is_set(ArgSettings::EmptyValues) &&
                val.is_empty_() &&
                matcher.contains(&*arg.name()) {
                return Err(Error::empty_value(arg, &*self.create_current_usage(matcher)));
            }
            if let Some(ref vtor) = arg.validator() {
                if let Err(e) = vtor(val.to_string_lossy().into_owned()) {
                    return Err(Error::value_validation(e));
                }
            }
            if matcher.needs_more_vals(arg) {
                return Ok(Some(arg.name()));
            }
            Ok(None)
        }

        fn parse_flag(&self, flag: &FlagBuilder<'a, 'b>, matcher: &mut ArgMatcher<'a>) -> ClapResult<()> {
            debugln!("fn=parse_flag;");
            validate_multiples!(self, flag, matcher);

            matcher.inc_occurrence_of(flag.name);
            // Increment or create the group "args"
            self.groups_for_arg(flag.name).and_then(|vec| Some(matcher.inc_occurrences_of(&*vec)));

            Ok(())
        }

        fn validate_blacklist(&self, matcher: &mut ArgMatcher) -> ClapResult<()> {
            debugln!("fn=validate_blacklist;");
            macro_rules! build_err {
                ($me:ident, $name:expr, $matcher:ident) => ({
                    debugln!("macro=build_err;");
                    let c_with = $me.blacklisted_from($name, &$matcher);
                    debugln!("'{:?}' conflicts with '{}'", c_with, $name);
                    let usg = $me.create_current_usage($matcher);
                    if let Some(f) = $me.flags.iter().filter(|f| f.name == $name).next() {
                        debugln!("It was a flag...");
                        Error::argument_conflict(f, c_with, &*usg)
                    } else if let Some(o) = $me.opts.iter()
                                                     .filter(|o| o.name == $name)
                                                     .next() {
                        debugln!("It was an option...");
                        Error::argument_conflict(o, c_with, &*usg)
                    } else {
                        match $me.positionals.values()
                                                .filter(|p| p.name == $name)
                                                .next() {
                            Some(p) => {
                                debugln!("It was a positional...");
                                Error::argument_conflict(p, c_with, &*usg)
                            },
                            None    => panic!(INTERNAL_ERROR_MSG)
                        }
                    }
                });
            }
            for name in &self.blacklist {
                debugln!("Checking blacklisted name: {}", name);
                if self.groups.contains_key(name) {
                    debugln!("groups contains it...");
                    for n in self.arg_names_in_group(name) {
                        debugln!("Checking arg '{}' in group...", n);
                        if matcher.contains(&n) {
                            debugln!("matcher contains it...");
                            return Err(build_err!(self, n, matcher));
                        }
                    }
                } else if matcher.contains(name) {
                    debugln!("matcher contains it...");
                    return Err(build_err!(self, *name, matcher));
                }
            }
            Ok(())
        }

        fn validate_num_args(&self, matcher: &mut ArgMatcher) -> ClapResult<()> {
            debugln!("fn=validate_num_args;");
            for (name, ma) in matcher.iter() {
                if self.groups.contains_key(&**name) {
                    continue;
                } else {
                    if let Some(opt) = self.opts
                                         .iter()
                                         .filter(|o| &o.name == name)
                                         .next() {
                        try!(self._validate_num_vals(opt, ma, matcher));
                    } else if let Some(pos) = self.positionals
                                         .values()
                                         .filter(|p| &p.name == name)
                                         .next() {
                        try!(self._validate_num_vals(pos, ma, matcher));
                    }
                }
            }
            Ok(())
        }

        fn _validate_num_vals<A>(&self, a: &A, ma: &MatchedArg, matcher: &ArgMatcher) -> ClapResult<()>
            where A: AnyArg<'a, 'b> + Display
        {
            debugln!("fn=_validate_num_vals;");
            if let Some(num) = a.num_vals() {
                debugln!("num_vals set: {}", num);
                let should_err = if a.is_set(ArgSettings::Multiple) {
                    ((ma.vals.len() as u64) % num) != 0
                } else {
                    num != (ma.vals.len() as u64)
                };
                if should_err {
                    debugln!("Sending error WrongNumberOfValues");
                    return Err(Error::wrong_number_of_values(
                        a,
                        num,
                        if a.is_set(ArgSettings::Multiple) {
                            (ma.vals.len() % num as usize)
                        } else {
                            ma.vals.len()
                        },
                        if ma.vals.len() == 1 ||
                            (a.is_set(ArgSettings::Multiple) &&
                                (ma.vals.len() % num as usize) == 1) {
                            "as"
                        } else {
                            "ere"
                        },
                        &*self.create_current_usage(matcher)));
                }
            }
            if let Some(num) = a.max_vals() {
                debugln!("max_vals set: {}", num);
                if (ma.vals.len() as u64) > num {
                    debugln!("Sending error TooManyValues");
                    return Err(Error::too_many_values(
                        ma.vals.get(ma.vals.keys()
                                    .last()
                                    .expect(INTERNAL_ERROR_MSG))
                            .expect(INTERNAL_ERROR_MSG).to_str().expect(INVALID_UTF8),
                        a,
                        &*self.create_current_usage(matcher)));
                }
            }
            if let Some(num) = a.min_vals() {
                debugln!("min_vals set: {}", num);
                if (ma.vals.len() as u64) < num {
                    debugln!("Sending error TooFewValues");
                    return Err(Error::too_few_values(
                        a,
                        num,
                        ma.vals.len(),
                        &*self.create_current_usage(matcher)));
                }
            }
            Ok(())
        }

        fn validate_required(&self, matcher: &ArgMatcher) -> ClapResult<()> {
            'outer: for name in &self.required {
                if matcher.contains(name) {
                    continue 'outer;
                }
                if let Some(grp) = self.groups.get(name) {
                    for arg in &grp.args {
                        if matcher.contains(arg) { continue 'outer; }
                    }
                }
                if self.groups.values().any(|g| g.args.contains(name)) {
                    continue 'outer;
                }
                if let Some(a) = self.flags.iter().filter(|f| &f.name == name).next() {
                    if self.is_missing_required_ok(a, matcher) { continue 'outer; }
                } else if let Some(a) = self.opts.iter().filter(|o| &o.name == name).next() {
                    if self.is_missing_required_ok(a, matcher) { continue 'outer; }
                } else if let Some(a) = self.positionals.values().filter(|p| &p.name == name).next() {
                    if self.is_missing_required_ok(a, matcher) { continue 'outer; }
                }
                let err = if self.settings.is_set(AppSettings::ArgRequiredElseHelp) && matcher.is_empty() {
                    self._help().unwrap_err()
                } else {
                    let mut reqs = self.required.iter().map(|&r| &*r).collect::<Vec<_>>();
                    reqs.dedup();
                    Error::missing_required_argument(
                    &*self.get_required_from(&*reqs, Some(matcher))
                          .iter()
                          .fold(String::new(),
                              |acc, s| acc + &format!("\n    {}", Format::Error(s))[..]),
                    &*self.create_current_usage(matcher))
                };
                return Err(err);
            }
            Ok(())
        }

        fn is_missing_required_ok<A>(&self, a: &A, matcher: &ArgMatcher) -> bool where A: AnyArg<'a, 'b> {
            if let Some(bl) = a.blacklist() {
                for n in bl.iter() {
                    if matcher.contains(n)
                        || self.groups
                                .get(n)
                                .map_or(false, |g| g.args.iter().any(|an| matcher.contains(an))) {
                        return true;
                    }
                }
            } else if let Some(ru) = a.required_unless() {
                for n in ru.iter() {
                    if matcher.contains(n)
                        || self.groups
                                .get(n)
                                .map_or(false, |g| g.args.iter().any(|an| matcher.contains(an))) {
                        if !a.is_set(ArgSettings::RequiredUnlessAll) {
                            return true;
                        }
                    } else {
                        return false;
                    }
                }
                return true;
            }
            false
        }

        fn did_you_mean_error(&self, arg: &str, matcher: &mut ArgMatcher<'a>) -> ClapResult<()> {
            // Didn't match a flag or option...maybe it was a typo and close to one
            let suffix = suggestions::did_you_mean_suffix(arg,
                                                  self.long_list.iter(),
                                                  suggestions::DidYouMeanMessageStyle::LongFlag);

            // Add the arg to the matches to build a proper usage string
            if let Some(name) = suffix.1 {
                if let Some(opt) = self.opts
                                        .iter()
                                        .filter(|o| o.long.is_some() && o.long.unwrap() == name)
                                        .next() {
                    self.groups_for_arg(&*opt.name).and_then(|grps| Some(matcher.inc_occurrences_of(&*grps)));
                    matcher.insert(&*opt.name);
                } else if let Some(flg) = self.flags
                                           .iter()
                                           .filter(|f| f.long.is_some() && f.long.unwrap() == name)
                                           .next() {
                    self.groups_for_arg(&*flg.name).and_then(|grps| Some(matcher.inc_occurrences_of(&*grps)));
                    matcher.insert(&*flg.name);
                }
            }

            let used_arg = format!("--{}", arg);
            Err(Error::unknown_argument(&*used_arg, &*suffix.0, &*self.create_current_usage(matcher)))
        }

        // Creates a usage string if one was not provided by the user manually. This happens just
        // after all arguments were parsed, but before any subcommands have been parsed
        // (so as to give subcommands their own usage recursively)
        pub fn create_usage(&self, used: &[&str]) -> String {
            debugln!("fn=create_usage;");
            let mut usage = String::with_capacity(75);
            usage.push_str("USAGE:\n    ");
            usage.push_str(&self.create_usage_no_title(&used));
            usage
        }

        // Creates a usage string (*without title*) if one was not provided by the user
        // manually. This happens just
        // after all arguments were parsed, but before any subcommands have been parsed
        // (so as to give subcommands their own usage recursively)
        pub fn create_usage_no_title(&self, used: &[&str]) -> String {
            debugln!("fn=create_usage_no_title;");
            let mut usage = String::with_capacity(75);
            if let Some(u) = self.meta.usage_str {
                usage.push_str(&*u);
            } else if used.is_empty() {
                usage.push_str(&*self.meta.usage
                                     .as_ref()
                                     .unwrap_or(self.meta.bin_name
                                                    .as_ref()
                                                    .unwrap_or(&self.meta.name)));
                let mut reqs: Vec<&str> = self.required().map(|r| &**r).collect();
                reqs.dedup();
                let req_string = self.get_required_from(&reqs, None)
                                     .iter()
                                     .fold(String::new(), |a, s| a + &format!(" {}", s)[..]);

                if self.has_flags() && !self.is_set(AppSettings::UnifiedHelpMessage) {
                    usage.push_str(" [FLAGS]");
                } else {
                    usage.push_str(" [OPTIONS]");
                }
                if !self.is_set(AppSettings::UnifiedHelpMessage)
                    && self.has_opts()
                    && self.opts.iter().any(|a| !a.settings.is_set(ArgSettings::Required)) {
                    usage.push_str(" [OPTIONS]");
                }

                usage.push_str(&req_string[..]);

                // places a '--' in the usage string if there are args and options
                // supporting multiple values
                if self.has_positionals()
                    && self.opts.iter().any(|a| a.settings.is_set(ArgSettings::Multiple))
                       // || self.positionals.values().any(|a| a.settings.is_set(ArgSettings::Multiple)))
                    && self.positionals.values().any(|a| !a.settings.is_set(ArgSettings::Required))
                    && !self.has_subcommands() {
                    usage.push_str(" [--]")
                }
                if self.has_positionals()
                    && self.positionals.values().any(|a| !a.settings.is_set(ArgSettings::Required)) {
                    usage.push_str(" [ARGS]");
                }

                if self.has_subcommands() && !self.is_set(AppSettings::SubcommandRequired) {
                    usage.push_str(" [SUBCOMMAND]");
                } else if self.is_set(AppSettings::SubcommandRequired) && self.has_subcommands() {
                    usage.push_str(" <SUBCOMMAND>");
                }
            } else {
                self.smart_usage(&mut usage, used);
            }

            usage.shrink_to_fit();
            usage
        }

        // Creates a context aware usage string, or "smart usage" from currently used
        // args, and requirements
        fn smart_usage(&self, usage: &mut String, used: &[&str]) {
            debugln!("fn=smart_usage;");
            let mut hs: Vec<&str> = self.required().map(|s| &**s).collect();
            hs.extend_from_slice(used);

            let r_string = self.get_required_from(&hs, None)
                                         .iter()
                                         .fold(String::new(), |acc, s| acc + &format!(" {}", s)[..]);

            usage.push_str(&self.meta.usage.as_ref()
                                      .unwrap_or(self.meta.bin_name.as_ref().unwrap_or(&self.meta.name))[..]);
            usage.push_str(&*r_string);
            if self.is_set(AppSettings::SubcommandRequired) {
                usage.push_str(" <SUBCOMMAND>");
            }
        }

        // Prints the version to the user and exits if quit=true
        fn print_version<W: Write>(&self, w: &mut W) -> ClapResult<()> {
            try!(self.write_version(w));
            w.flush().map_err(Error::from)
        }

        fn write_version<W: Write>(&self, w: &mut W) -> io::Result<()> {
            if let Some(bn) = self.meta.bin_name.as_ref() {
                if bn.contains(' ') {
                    // Incase we're dealing with subcommands i.e. git mv is translated to git-mv
                    writeln!(w, "{} {}", bn.replace(" ", "-"), self.meta.version.unwrap_or("".into()))
                } else {
                    writeln!(w, "{} {}", &self.meta.name[..], self.meta.version.unwrap_or("".into()))
                }
            } else {
                writeln!(w, "{} {}", &self.meta.name[..], self.meta.version.unwrap_or("".into()))
            }
        }

        pub fn print_help(&self) -> ClapResult<()> {
            let out = io::stdout();
            let mut buf_w = BufWriter::new(out.lock());
            self.write_help(&mut buf_w)
        }

        #[cfg_attr(feature = "lints", allow(for_kv_map))]
        pub fn write_help<W: Write>(&self, w: &mut W) -> ClapResult<()> {
            Help::write_parser_help(w, &self)
        }

        fn add_defaults(&mut self, matcher: &mut ArgMatcher<'a>) -> ClapResult<()> {
            macro_rules! add_val {
                ($_self:ident, $a:ident, $m:ident) => {
                    if $m.get($a.name).is_none() {
                        try!($_self.add_val_to_arg($a, OsStr::new($a.default_val.as_ref().unwrap()), $m));
                        arg_post_processing!($_self, $a, $m);
                    }
                };
            }
            for o in self.opts.iter().filter(|o| o.default_val.is_some()) {
                add_val!(self, o, matcher);
            }
            for p in self.positionals.values().filter(|p| p.default_val.is_some()) {
                add_val!(self, p, matcher);
            }
            Ok(())
        }

        pub fn iter_flags(&self) -> Iter<FlagBuilder> {
            self.flags.iter()
        }

        pub fn iter_opts(&self) -> Iter<OptBuilder> {
            self.opts.iter()
        }

        pub fn iter_positionals(&self) -> vec_map::Values<PosBuilder> {
            self.positionals.values()
        }
    }

    impl<'a, 'b> Clone for Parser<'a, 'b> where 'a: 'b {
        fn clone(&self) -> Self {
            Parser {
                required: self.required.clone(),
                short_list: self.short_list.clone(),
                long_list: self.long_list.clone(),
                blacklist: self.blacklist.clone(),
                flags: self.flags.clone(),
                opts: self.opts.clone(),
                positionals: self.positionals.clone(),
                subcommands: self.subcommands.clone(),
                groups: self.groups.clone(),
                global_args: self.global_args.clone(),
                overrides: self.overrides.clone(),
                help_short: self.help_short,
                version_short: self.version_short,
                settings: self.settings.clone(),
                meta: self.meta.clone(),
            }
        }
    }

# Help

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