From 87ecc794d5f2aa42eaaabc084eab179b3b7b1da4 Mon Sep 17 00:00:00 2001
From: Eric Githinji <egithinji@google.com>
Date: Fri, 28 Feb 2025 18:35:56 +0000
Subject: [PATCH] Use dbg! instead of println! in deep dive sessions.

Part of #2478 to clean up code blocks when all that is needed is a trivial debug print statement.
The deep dive sessions didn't have that many occurrences of trivial println!
statements.

I believe this can close #2478.
---
 CONTRIBUTING.md                      | 10 +++++-----
 src/bare-metal/useful-crates/spin.md |  4 ++--
 src/concurrency/threads/scoped.md    |  4 ++--
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a5ecccc37889..fd02e8d41586 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -19,11 +19,11 @@ match ANCHOR comments in the `exercise.rs` file. Each segment also has a
 `Cargo.toml`. The result is that `exercise.rs` is built and tested by
 `cargo test`.
 
-For segments on day 1, exercises should use `fn main() { .. }` and `println!`,
-with students visually verifying the correct output. On subsequent days, prefer
-tests and omit `fn main() { .. }`. However, where tests would be difficult and
-visual verification is more natural (such as in the Logger exercise), using
-`fn main { .. }` is OK.
+For segments on day 1, exercises should use `fn main() { .. }` and `dbg!` or
+`println!`, with students visually verifying the correct output. On subsequent
+days, prefer tests and omit `fn main() { .. }`. However, where tests would be
+difficult and visual verification is more natural (such as in the Logger
+exercise), using `fn main { .. }` is OK.
 
 Especially for exercises without tests, consider including tests in
 `exercise.rs` that do not appear in either `exercise.md` or `solution.md`, as
diff --git a/src/bare-metal/useful-crates/spin.md b/src/bare-metal/useful-crates/spin.md
index 42f9f1de27d1..13fc863f1e18 100644
--- a/src/bare-metal/useful-crates/spin.md
+++ b/src/bare-metal/useful-crates/spin.md
@@ -15,9 +15,9 @@ use spin::mutex::SpinMutex;
 static COUNTER: SpinMutex<u32> = SpinMutex::new(0);
 
 fn main() {
-    println!("count: {}", COUNTER.lock());
+    dbg!(COUNTER.lock());
     *COUNTER.lock() += 2;
-    println!("count: {}", COUNTER.lock());
+    dbg!(COUNTER.lock());
 }
 ```
 
diff --git a/src/concurrency/threads/scoped.md b/src/concurrency/threads/scoped.md
index 339645196f88..3bf65ff6c5ed 100644
--- a/src/concurrency/threads/scoped.md
+++ b/src/concurrency/threads/scoped.md
@@ -12,7 +12,7 @@ use std::thread;
 fn foo() {
     let s = String::from("Hello");
     thread::spawn(|| {
-        println!("Length: {}", s.len());
+        dbg!(s.len());
     });
 }
 
@@ -30,7 +30,7 @@ fn foo() {
     let s = String::from("Hello");
     thread::scope(|scope| {
         scope.spawn(|| {
-            println!("Length: {}", s.len());
+            dbg!(s.len());
         });
     });
 }