update listings ch07 close #654

listings/ch07-managing-growing-projects/quick-reference-example/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "backyard"
+version = "0.1.0"

listings/ch07-managing-growing-projects/quick-reference-example/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "backyard"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

listings/ch07-managing-growing-projects/quick-reference-example/output.txt

@@ -0,0 +1,5 @@
+$ cargo run
+   Compiling backyard v0.1.0 (file:///projects/backyard)
+    Finished dev [unoptimized + debuginfo] target(s) in 0.36s
+     Running `target/debug/backyard`
+I'm growing Asparagus!

listings/ch07-managing-growing-projects/quick-reference-example/src/garden.rs

@@ -0,0 +1 @@
+pub mod vegetables;

listings/ch07-managing-growing-projects/quick-reference-example/src/garden/vegetables.rs

@@ -0,0 +1,2 @@
+#[derive(Debug)]
+pub struct Asparagus {}

listings/ch07-managing-growing-projects/quick-reference-example/src/main.rs

@@ -0,0 +1,8 @@
+use crate::garden::vegetables::Asparagus;
+
+pub mod garden;
+
+fn main() {
+    let plant = Asparagus {};
+    println!("I'm growing {:?}!", plant);
+}