1 files changed, 31 insertions, 0 deletions
diff --git a/meap/meap-code/ch4/ch4-rc-refcell-groundstation.rs b/meap/meap-code/ch4/ch4-rc-refcell-groundstation.rs
new file mode 100644
index 0000000..d0e27ee
--- /dev/null
+++ b/meap/meap-code/ch4/ch4-rc-refcell-groundstation.rs
@@ -0,0 +1,31 @@
+use std::rc::Rc;
+use std::cell::RefCell;
+
+#[derive(Debug)]
+struct GroundStation {
+  radio_freq: f64 // Mhz
+}
+
+fn main() {
+  let base: Rc<RefCell<GroundStation>> = Rc::new(RefCell::new(
+    GroundStation {
+      radio_freq: 87.65
+    }
+  ));
+
+  println!("base: {:?}", base);
+
+  { // introduce a new scope
+    let mut base_2 = base.borrow_mut();
+    base_2.radio_freq -= 12.34;
+    println!("base_2: {:?}", base_2);
+  }
+
+  println!("base: {:?}", base);
+
+  let mut base_3 = base.borrow_mut();
+  base_3.radio_freq += 43.21;
+
+  println!("base: {:?}", base);
+  println!("base_3: {:?}", base_3);
+}