perf: Misc simplifications for code size

This dropped a fraction of a KiB but it will at least not cause people
to ask if it'd help to simplify in the future.

Author: epage

src/builder/arg.rs

@@ -146,7 +146,7 @@ impl Arg {
     #[must_use]
     pub fn short(mut self, s: impl IntoResettable<char>) -> Self {
         if let Some(s) = s.into_resettable().into_option() {
-            assert!(s != '-', "short option name cannot be `-`");
+            debug_assert!(s != '-', "short option name cannot be `-`");
             self.short = Some(s);
         } else {
             self.short = None;
@@ -241,7 +241,7 @@ impl Arg {
     #[must_use]
     pub fn short_alias(mut self, name: impl IntoResettable<char>) -> Self {
         if let Some(name) = name.into_resettable().into_option() {
-            assert!(name != '-', "short alias name cannot be `-`");
+            debug_assert!(name != '-', "short alias name cannot be `-`");
             self.short_aliases.push((name, false));
         } else {
             self.short_aliases.clear();
@@ -301,7 +301,7 @@ impl Arg {
     #[must_use]
     pub fn short_aliases(mut self, names: impl IntoIterator<Item = char>) -> Self {
         for s in names {
-            assert!(s != '-', "short alias name cannot be `-`");
+            debug_assert!(s != '-', "short alias name cannot be `-`");
             self.short_aliases.push((s, false));
         }
         self
@@ -357,7 +357,7 @@ impl Arg {
     #[must_use]
     pub fn visible_short_alias(mut self, name: impl IntoResettable<char>) -> Self {
         if let Some(name) = name.into_resettable().into_option() {
-            assert!(name != '-', "short alias name cannot be `-`");
+            debug_assert!(name != '-', "short alias name cannot be `-`");
             self.short_aliases.push((name, true));
         } else {
             self.short_aliases.clear();
@@ -412,7 +412,7 @@ impl Arg {
     #[must_use]
     pub fn visible_short_aliases(mut self, names: impl IntoIterator<Item = char>) -> Self {
         for n in names {
-            assert!(n != '-', "short alias name cannot be `-`");
+            debug_assert!(n != '-', "short alias name cannot be `-`");
             self.short_aliases.push((n, true));
         }
         self

src/builder/command.rs

@@ -195,10 +195,6 @@ impl Command {
     /// [arguments]: Arg
     #[must_use]
     pub fn args(mut self, args: impl IntoIterator<Item = impl Into<Arg>>) -> Self {
-        let args = args.into_iter();
-        let (lower, _) = args.size_hint();
-        self.args.reserve(lower);
-
         for arg in args {
             self = self.arg(arg);
         }
@@ -407,10 +403,6 @@ impl Command {
     /// [`IntoIterator`]: std::iter::IntoIterator
     #[must_use]
     pub fn subcommands(mut self, subcmds: impl IntoIterator<Item = impl Into<Self>>) -> Self {
-        let subcmds = subcmds.into_iter();
-        let (lower, _) = subcmds.size_hint();
-        self.subcommands.reserve(lower);
-
         for subcmd in subcmds {
             self = self.subcommand(subcmd);
         }
@@ -2219,7 +2211,7 @@ impl Command {
     #[must_use]
     pub fn short_flag_alias(mut self, name: impl IntoResettable<char>) -> Self {
         if let Some(name) = name.into_resettable().into_option() {
-            assert!(name != '-', "short alias name cannot be `-`");
+            debug_assert!(name != '-', "short alias name cannot be `-`");
             self.short_flag_aliases.push((name, false));
         } else {
             self.short_flag_aliases.clear();
@@ -2310,7 +2302,7 @@ impl Command {
     #[must_use]
     pub fn short_flag_aliases(mut self, names: impl IntoIterator<Item = char>) -> Self {
         for s in names {
-            assert!(s != '-', "short alias name cannot be `-`");
+            debug_assert!(s != '-', "short alias name cannot be `-`");
             self.short_flag_aliases.push((s, false));
         }
         self
@@ -2402,7 +2394,7 @@ impl Command {
     #[must_use]
     pub fn visible_short_flag_alias(mut self, name: impl IntoResettable<char>) -> Self {
         if let Some(name) = name.into_resettable().into_option() {
-            assert!(name != '-', "short alias name cannot be `-`");
+            debug_assert!(name != '-', "short alias name cannot be `-`");
             self.short_flag_aliases.push((name, true));
         } else {
             self.short_flag_aliases.clear();
@@ -2491,7 +2483,7 @@ impl Command {
     #[must_use]
     pub fn visible_short_flag_aliases(mut self, names: impl IntoIterator<Item = char>) -> Self {
         for s in names {
-            assert!(s != '-', "short alias name cannot be `-`");
+            debug_assert!(s != '-', "short alias name cannot be `-`");
             self.short_flag_aliases.push((s, true));
         }
         self
@@ -4041,7 +4033,7 @@ impl Command {
                 .map(|arg| arg.get_id().clone())
                 .collect();
 
-            assert!(args_missing_help.is_empty(),
+            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(", ")
@@ -4299,7 +4291,7 @@ impl Command {
 
     #[inline]
     pub(crate) fn contains_short(&self, s: char) -> bool {
-        assert!(
+        debug_assert!(
             self.is_set(AppSettings::Built),
             "If Command::_build hasn't been called, manually search through Arg shorts"
         );

src/mkeymap.rs

@@ -90,11 +90,6 @@ impl MKeyMap {
         self.keys.iter().any(|x| x.key == key)
     }
 
-    /// Reserves capacity for at least additional more elements to be inserted
-    pub(crate) fn reserve(&mut self, additional: usize) {
-        self.args.reserve(additional);
-    }
-
     /// Push an argument in the map.
     pub(crate) fn push(&mut self, new_arg: Arg) {
         self.args.push(new_arg);