add example.rs

examples/example.rs

@@ -0,0 +1,38 @@
+// Copyright (c) 2017 Guillaume Pinot <texitoi(a)texitoi.eu>
+//
+// This work is free. You can redistribute it and/or modify it under
+// the terms of the Do What The Fuck You Want To Public License,
+// Version 2, as published by Sam Hocevar. See the COPYING file for
+// more details.
+
+extern crate structopt;
+#[macro_use]
+extern crate structopt_derive;
+
+use structopt::StructOpt;
+
+#[derive(StructOpt, Debug)]
+#[structopt(name = "example", about = "An example of StructOpt usage.")]
+struct Opt {
+    /// A flag, true if used in the command line.
+    #[structopt(short = "d", long = "debug", help = "Activate debug mode")]
+    debug: bool,
+
+    /// An argument of type float, with a default value.
+    #[structopt(short = "s", long = "speed", help = "Set speed", default_value = "42")]
+    speed: f64,
+
+    /// Needed parameter, the first on the command line.
+    #[structopt(help = "Input file")]
+    input: String,
+
+    /// An optional parameter, will be `None` if not present on the
+    /// command line.
+    #[structopt(help = "Output file, stdout if not present")]
+    output: Option<String>,
+}
+
+fn main() {
+    let opt = Opt::from_args();
+    println!("{:?}", opt);
+}