Some enum example

some_example/src/main.rs

@@ -0,0 +1,21 @@
+fn plus_one(x: Option<i32>) -> Option<i32> {
+    match x {
+        None => None,
+	Some(i) => Some(i+1),
+    }
+}
+
+fn main() {
+    let x = 5;
+
+    println!("Val: {}, plus one: {}", x, plus_one(Some(x)).unwrap_or(1));
+
+    let x = Some(x);
+
+    println!("Val: {}, plus one: {}", x.unwrap(), plus_one(x).expect("Bad val"));
+
+    let x = None;
+
+    println!("Val of none with default of 1: {}", x.unwrap_or(1));
+    println!("Val of none with expect will panic: {}", x.expect("This will be panic because we have a None value"));
+}