Care about lifetimes

1 files changed, 41 insertions, 0 deletions

diff --git a/lifetimes/src/main.rs b/lifetimes/src/main.rs
new file mode 100644
index 0000000..8dec31f
--- /dev/null
+++ b/lifetimes/src/main.rs
@@ -0,0 +1,41 @@
+fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
+    if x.len() > y.len() {
+        x
+    } else {
+        y
+    }
+}
+
+use std::fmt::Display;
+
+// generic type params, trait bound, and lifetimes
+fn longest_with_an_announcement<'a, T>(
+    x: &'a str, 
+    y: &'a str, 
+    ann: T,
+) -> &'a str
+where
+    T: Display,
+{
+    println!("Announcement! {}", ann);
+    if x.len() > y.len() {
+        x
+    } else {
+        y
+    }
+}
+
+fn main() {
+    let string1 = String::from("abcd");
+    let string2 = "xyz";
+
+    let result = longest(string1.as_str(), string2);
+    println!("The longest string is {}", result);
+
+    let result = longest_with_an_announcement(
+        string1.as_str(),
+        string2,
+        "Today is someone's birthday!",
+    );
+    println!("The longest string is {}", result);
+}