From 4dfc11d74ab02ac5765ae5d08fb750c91f4744b4 Mon Sep 17 00:00:00 2001
From: Hunter Kvalevog <hunter@kvog.sh>
Date: Fri, 2 Oct 2026 21:53:51 -0500
Subject: rustlings: move to rust/

---
 .../rustlings/solutions/16_lifetimes/lifetimes1.rs | 24 ++++++++++++++++++
 .../rustlings/solutions/16_lifetimes/lifetimes2.rs | 29 ++++++++++++++++++++++
 .../rustlings/solutions/16_lifetimes/lifetimes3.rs | 18 ++++++++++++++
 3 files changed, 71 insertions(+)
 create mode 100644 rust/rustlings/solutions/16_lifetimes/lifetimes1.rs
 create mode 100644 rust/rustlings/solutions/16_lifetimes/lifetimes2.rs
 create mode 100644 rust/rustlings/solutions/16_lifetimes/lifetimes3.rs

(limited to 'rust/rustlings/solutions/16_lifetimes')

diff --git a/rust/rustlings/solutions/16_lifetimes/lifetimes1.rs b/rust/rustlings/solutions/16_lifetimes/lifetimes1.rs
new file mode 100644
index 0000000..4f56834
--- /dev/null
+++ b/rust/rustlings/solutions/16_lifetimes/lifetimes1.rs
@@ -0,0 +1,24 @@
+// The Rust compiler needs to know how to check whether supplied references are
+// valid, so that it can let the programmer know if a reference is at risk of
+// going out of scope before it is used. Remember, references are borrows and do
+// not own their own data. What if their owner goes out of scope?
+
+fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
+    //    ^^^^     ^^          ^^          ^^
+    if x.len() > y.len() { x } else { y }
+}
+
+fn main() {
+    // You can optionally experiment here.
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_longest() {
+        assert_eq!(longest("abcd", "123"), "abcd");
+        assert_eq!(longest("abc", "1234"), "1234");
+    }
+}
diff --git a/rust/rustlings/solutions/16_lifetimes/lifetimes2.rs b/rust/rustlings/solutions/16_lifetimes/lifetimes2.rs
new file mode 100644
index 0000000..3ca4909
--- /dev/null
+++ b/rust/rustlings/solutions/16_lifetimes/lifetimes2.rs
@@ -0,0 +1,29 @@
+fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
+    if x.len() > y.len() { x } else { y }
+}
+
+fn main() {
+    let string1 = String::from("long string is long");
+    // Solution1: You can move `strings2` out of the inner block so that it is
+    // not dropped before the print statement.
+    let string2 = String::from("xyz");
+    let result;
+    {
+        result = longest(&string1, &string2);
+    }
+    println!("The longest string is '{result}'");
+    // `string2` dropped at the end of the function.
+
+    // =========================================================================
+
+    let string1 = String::from("long string is long");
+    let result;
+    {
+        let string2 = String::from("xyz");
+        result = longest(&string1, &string2);
+        // Solution2: You can move the print statement into the inner block so
+        // that it is executed before `string2` is dropped.
+        println!("The longest string is '{result}'");
+        // `string2` dropped here (end of the inner scope).
+    }
+}
diff --git a/rust/rustlings/solutions/16_lifetimes/lifetimes3.rs b/rust/rustlings/solutions/16_lifetimes/lifetimes3.rs
new file mode 100644
index 0000000..16a5a68
--- /dev/null
+++ b/rust/rustlings/solutions/16_lifetimes/lifetimes3.rs
@@ -0,0 +1,18 @@
+// Lifetimes are also needed when structs hold references.
+
+struct Book<'a> {
+    //     ^^^^ added a lifetime annotation
+    author: &'a str,
+    //       ^^
+    title: &'a str,
+    //      ^^
+}
+
+fn main() {
+    let book = Book {
+        author: "George Orwell",
+        title: "1984",
+    };
+
+    println!("{} by {}", book.title, book.author);
+}
-- 
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