Updated src/generic_types_traits_and_lifetimes/lifetimes.md'.

projects/dangling_ref_demo/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "dangling_ref_demo"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

projects/dangling_ref_demo/src/main.rs

@@ -0,0 +1,6 @@
+fn main() {
+    let x = 5;
+    let r = &x;
+
+    println! {"r: {r}"};
+}

projects/generic_lifetimes_demo/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "generic_lifetimes_demo"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

projects/generic_lifetimes_demo/src/main.rs

@@ -0,0 +1,15 @@
+fn main() {
+    let string1 = String::from("长字符串就是长");
+    let result;
+
+    {
+        let string2 = String::from("xyz");
+        result = longest(string1.as_str(), string2.as_str());
+    }
+    println! ("最长字符串为 {result}");
+}
+
+fn longest<'a>(x: &str, y: &str) -> &'a str {
+    let result = String::from("真正长的字符串");
+    result.as_str()
+}

projects/lifetime_in_struct_demo/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "lifetime_in_struct_demo"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

projects/lifetime_in_struct_demo/src/main.rs

@@ -0,0 +1,14 @@
+#[derive(Debug)]
+struct ImportantExcerpt<'a> {
+    part: &'a str,
+}
+
+fn main() {
+    let novel = String::from("请叫我 Ishmael。数年前.....");
+    let first_sentence = novel.split('。').next().unwrap();
+    let i = ImportantExcerpt {
+        part: first_sentence,
+    };
+
+    println! ("{i:?}");
+}