1 files changed, 36 insertions, 0 deletions
diff --git a/vendor/clap-3.2.20/examples/tutorial_builder/04_02_validate.rs b/vendor/clap-3.2.20/examples/tutorial_builder/04_02_validate.rs
new file mode 100644
index 000000000..ea2f32e67
--- /dev/null
+++ b/vendor/clap-3.2.20/examples/tutorial_builder/04_02_validate.rs
@@ -0,0 +1,36 @@
+use std::ops::RangeInclusive;
+
+use clap::{arg, command};
+
+fn main() {
+    let matches = command!() // requires `cargo` feature
+        .arg(
+            arg!(<PORT>)
+                .help("Network port to use")
+                .value_parser(port_in_range),
+        )
+        .get_matches();
+
+    // Note, it's safe to call unwrap() because the arg is required
+    let port: u16 = *matches
+        .get_one::<u16>("PORT")
+        .expect("'PORT' is required and parsing will fail if its missing");
+    println!("PORT = {}", port);
+}
+
+const PORT_RANGE: RangeInclusive<usize> = 1..=65535;
+
+fn port_in_range(s: &str) -> Result<u16, String> {
+    let port: usize = s
+        .parse()
+        .map_err(|_| format!("`{}` isn't a port number", s))?;
+    if PORT_RANGE.contains(&port) {
+        Ok(port as u16)
+    } else {
+        Err(format!(
+            "Port not in range {}-{}",
+            PORT_RANGE.start(),
+            PORT_RANGE.end()
+        ))
+    }
+}