add slice

single_file_tests/slice.rs

@@ -0,0 +1,31 @@
+
+// https://rust.cc/article?id=fa12f620-5dbd-4e61-a8c1-2529e71bc96b
+fn main() {
+    greet(&[]);
+    greet(&["alice"]);
+    greet(&["alice", "bob"]);
+    greet(&["alice", "bob", "tom"]);
+
+    let arr = [1, 2, 3];
+    println!("{}", match arr {
+        [_, _, 3] => "Ends with 3",
+        [_, _, _] => "Ends with something else",
+    });
+}
+
+fn greet(people: &[&str]) {
+    match people {
+        [] => println!("No noe here!"),
+        [one] => println!("Has one: {}", one),
+        [one, two] => println!("Has two: {} and {}", one, two),
+        many => println!("Has many: {:?}", many),
+    }
+}
+
+// UNSTABLE FEATURE:
+// fn first<T>(xs: &[T]) -> Option<&T> {
+//     match xs {
+//         [x, ..] => Some(x),
+//         [] => None,
+//     }
+// }