Add generics

book/generics/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "generics"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

book/generics/src/main.rs

@@ -0,0 +1,55 @@
+use core::alloc;
+
+struct List<T> {
+    list: Vec<T>,
+}
+
+impl List<usize> {
+    fn sum(&self) -> usize {
+        self.list.iter().sum()
+    }
+}
+
+impl List<String> {
+    fn sum(&self) -> String {
+        let mut merged_string = String::new();
+        for element in &self.list {
+            merged_string.push_str(element.as_str());
+        }
+        merged_string
+    }
+}
+
+struct Point<T> {
+    x: T,
+    y: T,
+}
+
+impl<T> Point<T> {
+    fn x(&self) -> &T {
+        &self.x
+    }
+}
+
+impl Point<f32> {
+    fn distance_from_origin(&self) -> f32 {
+        (self.x.powi(2) + self.y.powi(2)).sqrt()
+    }
+}
+
+fn main() {
+    let list_one = List { list: vec![1, 2, 3, 4, 5] };
+    let list_two = List { list: vec![String::from("hello"), String::from(" world")] };
+
+    let sum = list_one.sum();
+    let merged = list_two.sum();
+
+    println!("Sum -> {}", sum);
+    println!("Merged -> {}", merged);
+
+    let p_one = Point { x: 5, y: 10 };
+    let p_two = Point { x: 5.0, y: 10.0 };
+
+    println!("p_one.x = {}", p_one.x());
+    println!("p_two.distance_from_origin = {}", p_two.distance_from_origin());
+}