fix: Ease clap2->3 transition with renamed Settings

This brings back the old name of settings, just deprecated.  Since they
all map to the same bits in the bit field, this should work for
`setting` and `is_set`.  The only thing this lacks is being able to do
equality across variants, whcih seems like a minority case.

Removed settings have some extra care abouts that we'll need to look
into separately.

This is a part of clap-rs#2617

src/build/app/settings.rs

@@ -87,10 +87,16 @@ impl_settings! { AppSettings, AppFlags,
         => Flags::DISABLE_HELP_SC,
     DisableHelpFlag("disablehelpflag")
         => Flags::DISABLE_HELP_FLAG,
+    DisableHelpFlags("disablehelpflag")
+        => Flags::DISABLE_HELP_FLAG,
     DisableVersionFlag("disableversionflag")
         => Flags::DISABLE_VERSION_FLAG,
+    DisableVersion("disableversionflag")
+        => Flags::DISABLE_VERSION_FLAG,
     PropagateVersion("propagateversion")
         => Flags::PROPAGATE_VERSION,
+    GlobalVersion("propagateversion")
+        => Flags::PROPAGATE_VERSION,
     HidePossibleValuesInHelp("hidepossiblevaluesinhelp")
         => Flags::NO_POS_VALUES,
     HelpRequired("helprequired")
@@ -530,6 +536,10 @@ pub enum AppSettings {
     /// ```
     DisableHelpFlag,
 
+    /// Deprecated, see [`AppSettings::DisableHelpFlag`]
+    #[deprecated(since = "3.0.0", note = "Replaced with `AppSettings::DisableHelpFlag`")]
+    DisableHelpFlags,
+
     /// Disables the `help` [`subcommand`].
     ///
     /// # Examples
@@ -567,6 +577,13 @@ pub enum AppSettings {
     /// ```
     DisableVersionFlag,
 
+    /// Deprecated, see [`AppSettings::DisableVersionFlag`]
+    #[deprecated(
+        since = "3.0.0",
+        note = "Replaced with `AppSettings::DisableVersionFlag`"
+    )]
+    DisableVersion,
+
     /// Displays the arguments and [`subcommands`] in the help message in the order that they were
     /// declared in, and not alphabetically which is the default.
     ///
@@ -688,6 +705,13 @@ pub enum AppSettings {
     /// [`subcommands`]: crate::App::subcommand()
     PropagateVersion,
 
+    /// Deprecated, see [`AppSettings::PropagateVersion`]
+    #[deprecated(
+        since = "3.0.0",
+        note = "Replaced with `AppSettings::PropagateVersion`"
+    )]
+    GlobalVersion,
+
     /// Specifies that this [`subcommand`] should be hidden from help messages
     ///
     /// # Examples

src/build/arg/settings.rs

@@ -28,6 +28,7 @@ bitflags! {
         const HIDDEN_SHORT_H   = 1 << 18;
         const HIDDEN_LONG_H    = 1 << 19;
         const MULTIPLE_VALS    = 1 << 20;
+        const MULTIPLE         = Self::MULTIPLE_OCC.bits | Self::MULTIPLE_VALS.bits;
         #[cfg(feature = "env")]
         const HIDE_ENV         = 1 << 21;
         const UTF8_NONE        = 1 << 22;
@@ -49,6 +50,7 @@ impl_settings! { ArgSettings, ArgFlags,
     Required("required") => Flags::REQUIRED,
     MultipleOccurrences("multipleoccurrences") => Flags::MULTIPLE_OCC,
     MultipleValues("multiplevalues") => Flags::MULTIPLE_VALS,
+    Multiple("multiple") => Flags::MULTIPLE,
     ForbidEmptyValues("forbidemptyvalues") => Flags::NO_EMPTY_VALS,
     Hidden("hidden") => Flags::HIDDEN,
     TakesValue("takesvalue") => Flags::TAKES_VAL,
@@ -61,6 +63,7 @@ impl_settings! { ArgSettings, ArgFlags,
     RequireEquals("requireequals") => Flags::REQUIRE_EQUALS,
     Last("last") => Flags::LAST,
     IgnoreCase("ignorecase") => Flags::CASE_INSENSITIVE,
+    CaseInsensitive("ignorecase") => Flags::CASE_INSENSITIVE,
     #[cfg(feature = "env")]
     HideEnv("hideenv") => Flags::HIDE_ENV,
     #[cfg(feature = "env")]
@@ -87,6 +90,13 @@ pub enum ArgSettings {
     MultipleValues,
     /// Allows an arg to appear multiple times
     MultipleOccurrences,
+    /// Deprecated, see [`ArgSettings::MultipleOccurrences`] (most likely what you want) and
+    /// [`ArgSettings::MultipleValues`]
+    #[deprecated(
+        since = "3.0.0",
+        note = "Split into `ArgSettings::MultipleOccurrences` (most likely what you want)  and `ArgSettings::MultipleValues`"
+    )]
+    Multiple,
     /// Forbids an arg from accepting empty values such as `""`
     ForbidEmptyValues,
     /// Hides an arg from the help message
@@ -113,6 +123,9 @@ pub enum ArgSettings {
     HideDefaultValue,
     /// Possible values become case insensitive
     IgnoreCase,
+    /// Deprecated, see [`ArgSettings::IgnoreCase`]
+    #[deprecated(since = "3.0.0", note = "Replaced with `ArgSettings::IgnoreCase`")]
+    CaseInsensitive,
     /// Hides environment variable arguments from the help message
     #[cfg(feature = "env")]
     HideEnv,

src/macros.rs

@@ -549,6 +549,7 @@ macro_rules! impl_settings {
             }
 
             pub(crate) fn set(&mut self, s: $settings) {
+                #[allow(deprecated)]  // some Settings might be deprecated
                 match s {
                     $(
                         $(#[$inner $($args)*])*
@@ -558,6 +559,7 @@ macro_rules! impl_settings {
             }
 
             pub(crate) fn unset(&mut self, s: $settings) {
+                #[allow(deprecated)]  // some Settings might be deprecated
                 match s {
                     $(
                         $(#[$inner $($args)*])*
@@ -567,6 +569,7 @@ macro_rules! impl_settings {
             }
 
             pub(crate) fn is_set(&self, s: $settings) -> bool {
+                #[allow(deprecated)]  // some Settings might be deprecated
                 match s {
                     $(
                         $(#[$inner $($args)*])*
@@ -616,6 +619,8 @@ macro_rules! impl_settings {
         impl FromStr for $settings {
             type Err = String;
             fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
+                #[allow(deprecated)]  // some Settings might be deprecated
+                #[allow(unreachable_patterns)] // some Settings might be deprecated
                 match &*s.to_ascii_lowercase() {
                     $(
                         $(#[$inner $($args)*])*