Update to Rust 1.68

.github/workflows/main.yml

@@ -12,8 +12,8 @@ jobs:
     - name: Install Rust
       run: |
         rustup set profile minimal
-        rustup toolchain install 1.67 -c rust-docs
-        rustup default 1.67
+        rustup toolchain install 1.68 -c rust-docs
+        rustup default 1.68
     - name: Install mdbook
       run: |
         mkdir bin

listings/ch02-guessing-game-tutorial/listing-02-04/output.txt

@@ -8,17 +8,20 @@ $ cargo build
    Compiling rand v0.8.5
    Compiling guessing_game v0.1.0 (file:///projects/guessing_game)
 error[E0308]: mismatched types
-  --> src/main.rs:22:21
-   |
-22 |     match guess.cmp(&secret_number) {
-   |                 --- ^^^^^^^^^^^^^^ expected struct `String`, found integer
-   |                 |
-   |                 arguments to this function are incorrect
-   |
-   = note: expected reference `&String`
-              found reference `&{integer}`
+   --> src/main.rs:22:21
+    |
+22  |     match guess.cmp(&secret_number) {
+    |                 --- ^^^^^^^^^^^^^^ expected struct `String`, found integer
+    |                 |
+    |                 arguments to this method are incorrect
+    |
+    = note: expected reference `&String`
+               found reference `&{integer}`
 note: associated function defined here
-  --> /rustc/d5a82bbd26e1ad8b7401f6a718a9c57c96905483/library/core/src/cmp.rs:783:8
+   --> /Users/carolnichols/.rustup/toolchains/1.68-aarch64-apple-darwin/lib/rustlib/src/rust/library/core/src/cmp.rs:781:8
+    |
+781 |     fn cmp(&self, other: &Self) -> Ordering;
+    |        ^^^
 
 For more information about this error, try `rustc --explain E0308`.
 error: could not compile `guessing_game` due to previous error

listings/ch03-common-programming-concepts/no-listing-05-mut-cant-change-types/output.txt

@@ -7,6 +7,12 @@ error[E0308]: mismatched types
   |                      ----- expected due to this value
 3 |     spaces = spaces.len();
   |              ^^^^^^^^^^^^ expected `&str`, found `usize`
+  |
+help: try removing the method call
+  |
+3 -     spaces = spaces.len();
+3 +     spaces = spaces;
+  |
 
 For more information about this error, try `rustc --explain E0308`.
 error: could not compile `variables` due to previous error

listings/ch03-common-programming-concepts/output-only-01-no-type-annotations/output.txt

@@ -8,8 +8,8 @@ error[E0282]: type annotations needed
   |
 help: consider giving `guess` an explicit type
   |
-2 |     let guess: _ = "42".parse().expect("Not a number!");
-  |              +++
+2 |     let guess: /* Type */ = "42".parse().expect("Not a number!");
+  |              ++++++++++++
 
 For more information about this error, try `rustc --explain E0282`.
 error: could not compile `no_type_annotations` due to previous error

listings/ch04-understanding-ownership/listing-04-06/output.txt

@@ -3,10 +3,13 @@ $ cargo run
 error[E0596]: cannot borrow `*some_string` as mutable, as it is behind a `&` reference
  --> src/main.rs:8:5
   |
-7 | fn change(some_string: &String) {
-  |                        ------- help: consider changing this to be a mutable reference: `&mut String`
 8 |     some_string.push_str(", world");
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `some_string` is a `&` reference, so the data it refers to cannot be borrowed as mutable
+  |
+help: consider changing this to be a mutable reference
+  |
+7 | fn change(some_string: &mut String) {
+  |                        ~~~~~~~~~~~
 
 For more information about this error, try `rustc --explain E0596`.
 error: could not compile `ownership` due to previous error

listings/ch06-enums-and-pattern-matching/no-listing-10-non-exhaustive-match/output.txt

@@ -1,22 +1,25 @@
 $ cargo run
    Compiling enums v0.1.0 (file:///projects/enums)
 error[E0004]: non-exhaustive patterns: `None` not covered
- --> src/main.rs:3:15
-  |
-3 |         match x {
-  |               ^ pattern `None` not covered
-  |
+   --> src/main.rs:3:15
+    |
+3   |         match x {
+    |               ^ pattern `None` not covered
+    |
 note: `Option<i32>` defined here
- --> /rustc/d5a82bbd26e1ad8b7401f6a718a9c57c96905483/library/core/src/option.rs:518:1
-  |
-  = note: 
-/rustc/d5a82bbd26e1ad8b7401f6a718a9c57c96905483/library/core/src/option.rs:522:5: not covered
-  = note: the matched value is of type `Option<i32>`
+   --> /Users/carolnichols/.rustup/toolchains/1.68-aarch64-apple-darwin/lib/rustlib/src/rust/library/core/src/option.rs:566:5
+    |
+562 | pub enum Option<T> {
+    | ------------------
+...
+566 |     None,
+    |     ^^^^ not covered
+    = note: the matched value is of type `Option<i32>`
 help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown
-  |
-4 ~             Some(i) => Some(i + 1),
-5 ~             None => todo!(),
-  |
+    |
+4   ~             Some(i) => Some(i + 1),
+5   ~             None => todo!(),
+    |
 
 For more information about this error, try `rustc --explain E0004`.
 error: could not compile `enums` due to previous error

listings/ch15-smart-pointers/listing-15-21/output.txt

@@ -3,11 +3,13 @@ $ cargo test
 error[E0596]: cannot borrow `self.sent_messages` as mutable, as it is behind a `&` reference
   --> src/lib.rs:58:13
    |
-2  |     fn send(&self, msg: &str);
-   |             ----- help: consider changing that to be a mutable reference: `&mut self`
-...
 58 |             self.sent_messages.push(String::from(message));
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `self` is a `&` reference, so the data it refers to cannot be borrowed as mutable
+   |
+help: consider changing that to be a mutable reference
+   |
+2  |     fn send(&mut self, msg: &str);
+   |             ~~~~~~~~~
 
 For more information about this error, try `rustc --explain E0596`.
 error: could not compile `limit-tracker` due to previous error

listings/ch15-smart-pointers/no-listing-01-cant-borrow-immutable-as-mutable/output.txt

@@ -3,10 +3,13 @@ $ cargo run
 error[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable
  --> src/main.rs:3:13
   |
-2 |     let x = 5;
-  |         - help: consider changing this to be mutable: `mut x`
 3 |     let y = &mut x;
   |             ^^^^^^ cannot borrow as mutable
+  |
+help: consider changing this to be mutable
+  |
+2 |     let mut x = 5;
+  |         +++
 
 For more information about this error, try `rustc --explain E0596`.
 error: could not compile `borrowing` due to previous error

listings/ch16-fearless-concurrency/listing-16-14/output.txt

@@ -1,30 +1,31 @@
 $ cargo run
    Compiling shared-state v0.1.0 (file:///projects/shared-state)
 error[E0277]: `Rc<Mutex<i32>>` cannot be sent between threads safely
-  --> src/main.rs:11:36
-   |
-11 |           let handle = thread::spawn(move || {
-   |                        ------------- ^------
-   |                        |             |
-   |  ______________________|_____________within this `[closure@src/main.rs:11:36: 11:43]`
-   | |                      |
-   | |                      required by a bound introduced by this call
-12 | |             let mut num = counter.lock().unwrap();
-13 | |
-14 | |             *num += 1;
-15 | |         });
-   | |_________^ `Rc<Mutex<i32>>` cannot be sent between threads safely
-   |
-   = help: within `[closure@src/main.rs:11:36: 11:43]`, the trait `Send` is not implemented for `Rc<Mutex<i32>>`
+   --> src/main.rs:11:36
+    |
+11  |           let handle = thread::spawn(move || {
+    |                        ------------- ^------
+    |                        |             |
+    |  ______________________|_____________within this `[closure@src/main.rs:11:36: 11:43]`
+    | |                      |
+    | |                      required by a bound introduced by this call
+12  | |             let mut num = counter.lock().unwrap();
+13  | |
+14  | |             *num += 1;
+15  | |         });
+    | |_________^ `Rc<Mutex<i32>>` cannot be sent between threads safely
+    |
+    = help: within `[closure@src/main.rs:11:36: 11:43]`, the trait `Send` is not implemented for `Rc<Mutex<i32>>`
 note: required because it's used within this closure
-  --> src/main.rs:11:36
-   |
-11 |         let handle = thread::spawn(move || {
-   |                                    ^^^^^^^
+   --> src/main.rs:11:36
+    |
+11  |         let handle = thread::spawn(move || {
+    |                                    ^^^^^^^
 note: required by a bound in `spawn`
-  --> /rustc/d5a82bbd26e1ad8b7401f6a718a9c57c96905483/library/std/src/thread/mod.rs:704:8
-   |
-   = note: required by this bound in `spawn`
+   --> /Users/carolnichols/.rustup/toolchains/1.68-aarch64-apple-darwin/lib/rustlib/src/rust/library/std/src/thread/mod.rs:712:8
+    |
+712 |     F: Send + 'static,
+    |        ^^^^ required by this bound in `spawn`
 
 For more information about this error, try `rustc --explain E0277`.
 error: could not compile `shared-state` due to previous error

listings/ch18-patterns-and-matching/listing-18-08/output.txt

@@ -1,24 +1,15 @@
 $ cargo run
    Compiling patterns v0.1.0 (file:///projects/patterns)
-error[E0005]: refutable pattern in local binding: `None` not covered
+error[E0005]: refutable pattern in local binding
  --> src/main.rs:3:9
   |
 3 |     let Some(x) = some_option_value;
   |         ^^^^^^^ pattern `None` not covered
   |
   = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
   = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
-note: `Option<i32>` defined here
- --> /rustc/d5a82bbd26e1ad8b7401f6a718a9c57c96905483/library/core/src/option.rs:518:1
-  |
-  = note: 
-/rustc/d5a82bbd26e1ad8b7401f6a718a9c57c96905483/library/core/src/option.rs:522:5: not covered
   = note: the matched value is of type `Option<i32>`
-help: you might want to use `if let` to ignore the variant that isn't matched
-  |
-3 |     let x = if let Some(x) = some_option_value { x } else { todo!() };
-  |     ++++++++++                                 ++++++++++++++++++++++
-help: alternatively, you might want to use let else to handle the variant that isn't matched
+help: you might want to use `let else` to handle the variant that isn't matched
   |
 3 |     let Some(x) = some_option_value else { todo!() };
   |                                     ++++++++++++++++

listings/ch19-advanced-features/no-listing-02-impl-outlineprint-for-point/output.txt

@@ -1,10 +1,10 @@
 $ cargo run
    Compiling traits-example v0.1.0 (file:///projects/traits-example)
 error[E0277]: `Point` doesn't implement `std::fmt::Display`
-  --> src/main.rs:20:6
+  --> src/main.rs:20:23
    |
 20 | impl OutlinePrint for Point {}
-   |      ^^^^^^^^^^^^ `Point` cannot be formatted with the default formatter
+   |                       ^^^^^ `Point` cannot be formatted with the default formatter
    |
    = help: the trait `std::fmt::Display` is not implemented for `Point`
    = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead

listings/ch20-web-server/listing-20-22/output.txt

@@ -1,15 +1,18 @@
 $ cargo check
     Checking hello v0.1.0 (file:///projects/hello)
 error[E0507]: cannot move out of `worker.thread` which is behind a mutable reference
-  --> src/lib.rs:52:13
-   |
-52 |             worker.thread.join().unwrap();
-   |             ^^^^^^^^^^^^^ ------ `worker.thread` moved due to this method call
-   |             |
-   |             move occurs because `worker.thread` has type `JoinHandle<()>`, which does not implement the `Copy` trait
-   |
-note: this function takes ownership of the receiver `self`, which moves `worker.thread`
-  --> /rustc/d5a82bbd26e1ad8b7401f6a718a9c57c96905483/library/std/src/thread/mod.rs:1581:17
+    --> src/lib.rs:52:13
+     |
+52   |             worker.thread.join().unwrap();
+     |             ^^^^^^^^^^^^^ ------ `worker.thread` moved due to this method call
+     |             |
+     |             move occurs because `worker.thread` has type `JoinHandle<()>`, which does not implement the `Copy` trait
+     |
+note: `JoinHandle::<T>::join` takes ownership of the receiver `self`, which moves `worker.thread`
+    --> /Users/carolnichols/.rustup/toolchains/1.68-aarch64-apple-darwin/lib/rustlib/src/rust/library/std/src/thread/mod.rs:1589:17
+     |
+1589 |     pub fn join(self) -> Result<T> {
+     |                 ^^^^
 
 For more information about this error, try `rustc --explain E0507`.
 error: could not compile `hello` due to previous error

listings/ch20-web-server/no-listing-04-update-worker-definition/output.txt

@@ -1,17 +1,20 @@
 $ cargo check
     Checking hello v0.1.0 (file:///projects/hello)
 error[E0599]: no method named `join` found for enum `Option` in the current scope
-  --> src/lib.rs:52:27
-   |
-52 |             worker.thread.join().unwrap();
-   |                           ^^^^ method not found in `Option<JoinHandle<()>>`
-   |
+    --> src/lib.rs:52:27
+     |
+52   |             worker.thread.join().unwrap();
+     |                           ^^^^ method not found in `Option<JoinHandle<()>>`
+     |
 note: the method `join` exists on the type `JoinHandle<()>`
-  --> /rustc/d5a82bbd26e1ad8b7401f6a718a9c57c96905483/library/std/src/thread/mod.rs:1581:5
+    --> /Users/carolnichols/.rustup/toolchains/1.68-aarch64-apple-darwin/lib/rustlib/src/rust/library/std/src/thread/mod.rs:1589:5
+     |
+1589 |     pub fn join(self) -> Result<T> {
+     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: consider using `Option::expect` to unwrap the `JoinHandle<()>` value, panicking if the value is an `Option::None`
-   |
-52 |             worker.thread.expect("REASON").join().unwrap();
-   |                          +++++++++++++++++
+     |
+52   |             worker.thread.expect("REASON").join().unwrap();
+     |                          +++++++++++++++++
 
 error[E0308]: mismatched types
   --> src/lib.rs:72:22

rust-toolchain

@@ -1 +1 @@
-1.67
+1.68

src/title-page.md

@@ -2,7 +2,7 @@
 
 *by Steve Klabnik and Carol Nichols, with contributions from the Rust Community*
 
-This version of the text assumes you’re using Rust 1.67.1 (released 2023-02-09)
+This version of the text assumes you’re using Rust 1.68.2 (released 2023-03-28)
 or later. See the [“Installation” section of Chapter 1][install]<!-- ignore -->
 to install or update Rust.