feat(parser): Provide convenience accessor for Counts

examples/tutorial_builder/03_01_flag_count.rs

@@ -5,10 +5,5 @@ fn main() {
         .arg(arg!(-v - -verbose).action(ArgAction::Count))
         .get_matches();
 
-    println!(
-        "verbose: {:?}",
-        matches
-            .get_one::<u8>("verbose")
-            .expect("Count always defaulted")
-    );
+    println!("verbose: {:?}", matches.get_count("verbose"));
 }

src/builder/action.rs

@@ -183,16 +183,16 @@ pub enum ArgAction {
     /// assert!(matches.contains_id("flag"));
     /// assert_eq!(matches.occurrences_of("flag"), 0);
     /// assert_eq!(
-    ///     matches.get_one::<u8>("flag").copied(),
-    ///     Some(2)
+    ///     matches.get_count("flag"),
+    ///     2
     /// );
     ///
     /// let matches = cmd.try_get_matches_from(["mycmd"]).unwrap();
     /// assert!(matches.contains_id("flag"));
     /// assert_eq!(matches.occurrences_of("flag"), 0);
     /// assert_eq!(
-    ///     matches.get_one::<u8>("flag").copied(),
-    ///     Some(0)
+    ///     matches.get_count("flag"),
+    ///     0
     /// );
     /// ```
     Count,

src/parser/matches/arg_matches.rs

@@ -119,6 +119,37 @@ impl ArgMatches {
         MatchesError::unwrap(&internal_id, self.try_get_one(id))
     }
 
+    /// Gets the value of a specific [`ArgAction::Count`][crate::ArgAction::Count] flag
+    ///
+    /// # Panic
+    ///
+    /// If the argument's action is not [`ArgAction::Count`][crate::ArgAction::Count]
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use clap::Command;
+    /// # use clap::Arg;
+    /// let cmd = Command::new("mycmd")
+    ///     .arg(
+    ///         Arg::new("flag")
+    ///             .long("flag")
+    ///             .action(clap::ArgAction::Count)
+    ///     );
+    ///
+    /// let matches = cmd.clone().try_get_matches_from(["mycmd", "--flag", "--flag"]).unwrap();
+    /// assert_eq!(
+    ///     matches.get_count("flag"),
+    ///     2
+    /// );
+    /// ```
+    #[track_caller]
+    pub fn get_count(&self, id: &str) -> u8 {
+        *self
+            .get_one::<u8>(id)
+            .expect("ArgAction::Count is defaulted")
+    }
+
     /// Iterate over values of a specific option or positional argument.
     ///
     /// i.e. an argument that takes multiple values at runtime.