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-rw-r--r--exercises/16_lifetimes/lifetimes2.rs10
-rw-r--r--solutions/16_lifetimes/lifetimes2.rs34
2 files changed, 38 insertions, 6 deletions
diff --git a/exercises/16_lifetimes/lifetimes2.rs b/exercises/16_lifetimes/lifetimes2.rs
index 6e329e6..de5a5df 100644
--- a/exercises/16_lifetimes/lifetimes2.rs
+++ b/exercises/16_lifetimes/lifetimes2.rs
@@ -1,6 +1,4 @@
-// So if the compiler is just validating the references passed to the annotated
-// parameters and the return type, what do we need to change?
-
+// Don't change this function.
fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
if x.len() > y.len() {
x
@@ -10,11 +8,13 @@ fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
}
fn main() {
+ // TODO: Fix the compiler error by moving one line.
+
let string1 = String::from("long string is long");
let result;
{
let string2 = String::from("xyz");
- result = longest(string1.as_str(), string2.as_str());
+ result = longest(&string1, &string2);
}
- println!("The longest string is '{}'", result);
+ println!("The longest string is '{result}'");
}
diff --git a/solutions/16_lifetimes/lifetimes2.rs b/solutions/16_lifetimes/lifetimes2.rs
index 4e18198..b0f2ef1 100644
--- a/solutions/16_lifetimes/lifetimes2.rs
+++ b/solutions/16_lifetimes/lifetimes2.rs
@@ -1 +1,33 @@
-// Solutions will be available before the stable release. Thank you for testing the beta version 🥰
+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).
+ }
+}