RBE custom types structs activity 2

rustbyexample/.gitignore

@@ -1,4 +1,7 @@
+/custom_types/*
 /hello/*
 /primitives/*
+
+!/custom_types/*.rs
 !/hello/*.rs
 !/primitives/*.rs

rustbyexample/custom_types/custom_types_structs.rs

@@ -0,0 +1,79 @@
+#[derive(Debug)]
+struct Person {
+    name: String,
+    age: u8,
+}
+
+struct Unit;
+
+struct Pair(i32, f32);
+
+#[derive(Debug)]
+struct Point {
+    x: f32,
+    y: f32,
+}
+
+#[derive(Debug)]
+struct Rectangle {
+    top_left: Point,
+    bottom_right: Point,
+}
+
+fn rect_area(r: Rectangle) -> f32 {
+    (r.top_left.x - r.bottom_right.x) * (r.top_left.y - r.bottom_right.y)
+}
+
+fn square(p: &Point, d: f32) -> Rectangle {
+    Rectangle {
+        top_left: Point { x: p.x + d, y: p.y },
+        bottom_right: Point { x: p.x, y: p.y + d },
+    }
+}
+
+fn main() {
+    let name = String::from("Peter");
+    let age = 27;
+    let peter = Person { name, age };
+
+    println!("{:?}", peter);
+
+    let point: Point = Point { x: 10.3, y: 0.4 };
+
+    println!("point coordinates: ({}, {})", point.x, point.y);
+
+    let bottom_right = Point { x: 5.2, y: 0.2 };
+
+    println!("second point: ({}, {})", bottom_right.x, bottom_right.y);
+
+    let Point {
+        x: left_edge,
+        y: top_edge,
+    } = point;
+
+    let rect = Rectangle {
+        top_left: Point {
+            x: left_edge,
+            y: top_edge,
+        },
+        bottom_right: bottom_right,
+    };
+
+    let _unit = Unit;
+
+    let pair = Pair(1, 0.1);
+
+    println!("pair contains {:?} and {:?}", pair.0, pair.1);
+
+    let Pair(integer, decimal) = pair;
+
+    println!("pair contains {:?} and {:?}", integer, decimal);
+
+    println!("rect in {:?}", rect);
+    println!("area of rect is {}", rect_area(rect));
+
+    let lower_left = Point { x: 4.1, y: 11.3 };
+    let d = 7.7f32;
+    let sq = square(&lower_left, d);
+    println!("sq from point={:?} of d={} is {:?}", lower_left, d, sq);
+}

rustbyexample/primitives/primitives_array.rs

@@ -0,0 +1,26 @@
+use std::mem;
+
+fn analyze_slice(slice: &[i32]) {
+    println!("first element of the slice: {}", slice[0]);
+    println!("the slice has {} elements", slice.len());
+}
+
+fn main() {
+    let xs: [i32; 5] = [1, 2, 3, 4, 5];
+    let ys: [i32; 500] = [0; 500];
+
+    println!("first element of the array: {}", xs[0]);
+    println!("second element of the array: {}", xs[1]);
+
+    println!("number of elements in the array: {}", xs.len());
+
+    println!("array occupies {} bytes", mem::size_of_val(&xs));
+
+    println!("borrow the whole array as a slice");
+    analyze_slice(&xs);
+
+    println!("borrow a section of the array as a slice");
+    analyze_slice(&ys[1..4]);
+
+    // println!("{}", xs[5]);
+}