build(ariadne): vendor clap

third_party/crates/clap-4.6.6/examples/cargo-example.rs

@@ -0,0 +1,29 @@
+fn main() {
+    let cmd = clap::Command::new("cargo")
+        .bin_name("cargo")
+        .styles(CLAP_STYLING)
+        .subcommand_required(true)
+        .subcommand(
+            clap::command!("example").arg(
+                clap::arg!(--"manifest-path" <PATH>)
+                    .value_parser(clap::value_parser!(std::path::PathBuf)),
+            ),
+        );
+    let matches = cmd.get_matches();
+    let matches = match matches.subcommand() {
+        Some(("example", matches)) => matches,
+        _ => unreachable!("clap should ensure we don't get here"),
+    };
+    let manifest_path = matches.get_one::<std::path::PathBuf>("manifest-path");
+    println!("{manifest_path:?}");
+}
+
+// See also `clap_cargo::style::CLAP_STYLING`
+pub const CLAP_STYLING: clap::builder::styling::Styles = clap::builder::styling::Styles::styled()
+    .header(clap_cargo::style::HEADER)
+    .usage(clap_cargo::style::USAGE)
+    .literal(clap_cargo::style::LITERAL)
+    .placeholder(clap_cargo::style::PLACEHOLDER)
+    .error(clap_cargo::style::ERROR)
+    .valid(clap_cargo::style::VALID)
+    .invalid(clap_cargo::style::INVALID);