Move rust playground here

Signed-off-by: Carlos Maiolino <[email protected]>

1 files changed, 54 insertions, 0 deletions

diff --git a/rust/chap5/rectangle.rs b/rust/chap5/rectangle.rs
new file mode 100644
index 0000000..3b0ab98
--- /dev/null
+++ b/rust/chap5/rectangle.rs
@@ -0,0 +1,54 @@
+#[derive(Debug)]
+struct Rectangle {
+    width:  u32,
+    height: u32,
+}
+
+impl Rectangle {
+
+    // First parameter for methods must be named 'self', but the
+    // implementation provides some aliases like:
+    //
+    // self  == self: Self
+    // &self == self: &Self
+    //
+    // Note though that 'Self' is just an alias for the type referenced
+    // by the impl{} block. So, here:
+    //
+    // impl Rectangle {}
+    //      ^ Self is an alias to Rectangle
+
+    fn can_hold(&self, r: &Rectangle) -> bool {
+        self.width > r.width && self.height > r.height
+    }
+    // Here we can pass just a reference to a struct
+    // Rectangle, no need to transfer ownership
+    fn area(self: &Rectangle) -> u32 {
+        self.width * self.height
+    }
+
+    // Associated functions can be defined without a self parameter
+    // so they function can be namespaced with ::
+    fn square(size: u32) -> Self {
+        Self {
+            width: size,
+            height: size,
+        }
+    }
+}
+
+fn main() {
+    let rect = Rectangle {
+        width: dbg!(5 * 10),
+        height: 3,
+    };
+
+    let sqrt = Rectangle::square(90);
+
+    println!("{rect:#?} Area: {}", rect.area());
+
+    dbg!(&rect);
+    dbg!(&sqrt);
+
+    println!("{}", sqrt.can_hold(&rect));
+}