update original

rustbook-en/.git-blame-ignore-revs

@@ -1,2 +1,2 @@
 # Ran dprint fmt on the repo
-3a30e4c1
+3a30e4c1fbe641afc066b3af9eb01dcdf5ed8b24

rustbook-en/README.md

@@ -39,7 +39,7 @@ look right, but you _will_ still be able to build the book. To use the plugins,
 you should run:
 
 ```bash
-$ cargo install --locked --path packages/mdbook_trpl
+$ cargo install --locked --path packages/mdbook-trpl
 ```
 
 ## Building

rustbook-en/listings/ch11-writing-automated-tests/listing-11-03/src/lib.rs

@@ -1,4 +1,4 @@
-pub fn add(left: usize, right: usize) -> usize {
+pub fn add(left: u64, right: u64) -> u64 {
     left + right
 }
 

rustbook-en/listings/ch11-writing-automated-tests/no-listing-01-changing-test-name/src/lib.rs

@@ -1,4 +1,4 @@
-pub fn add(left: usize, right: usize) -> usize {
+pub fn add(left: u64, right: u64) -> u64 {
     left + right
 }
 

rustbook-en/listings/ch11-writing-automated-tests/no-listing-10-result-in-tests/src/lib.rs

@@ -1,4 +1,4 @@
-pub fn add(left: usize, right: usize) -> usize {
+pub fn add(left: u64, right: u64) -> u64 {
     left + right
 }
 

rustbook-en/listings/ch11-writing-automated-tests/no-listing-11-ignore-a-test/src/lib.rs

@@ -1,4 +1,4 @@
-pub fn add(left: usize, right: usize) -> usize {
+pub fn add(left: u64, right: u64) -> u64 {
     left + right
 }
 

rustbook-en/listings/ch20-advanced-features/no-listing-18-returns-closure/src/lib.rs

@@ -1,3 +1,3 @@
-fn returns_closure() -> dyn Fn(i32) -> i32 {
+fn returns_closure() -> impl Fn(i32) -> i32 {
     |x| x + 1
 }

rustbook-en/listings/ch20-advanced-features/no-listing-19-returns-closure-trait-object/src/main.rs

@@ -0,0 +1,15 @@
+fn main() {
+    let handlers = vec![returns_closure(), returns_initialized_closure(123)];
+    for handler in handlers {
+        let output = handler(5);
+        println!("{output}");
+    }
+}
+
+fn returns_closure() -> Box<dyn Fn(i32) -> i32> {
+    Box::new(|x| x + 1)
+}
+
+fn returns_initialized_closure(init: i32) -> Box<dyn Fn(i32) -> i32> {
+    Box::new(move |x| x + init)
+}

rustbook-en/src/ch01-02-hello-world.md

@@ -121,18 +121,16 @@ println!("Hello, world!");
 This line does all the work in this little program: it prints text to the
 screen. There are four important details to notice here.
 
-First, Rust style is to indent with four spaces, not a tab.
-
-Second, `println!` calls a Rust macro. If it had called a function instead, it
+First, `println!` calls a Rust macro. If it had called a function instead, it
 would be entered as `println` (without the `!`). We’ll discuss Rust macros in
 more detail in Chapter 20. For now, you just need to know that using a `!`
 means that you’re calling a macro instead of a normal function and that macros
 don’t always follow the same rules as functions.
 
-Third, you see the `"Hello, world!"` string. We pass this string as an argument
+Second, you see the `"Hello, world!"` string. We pass this string as an argument
 to `println!`, and the string is printed to the screen.
 
-Fourth, we end the line with a semicolon (`;`), which indicates that this
+Third, we end the line with a semicolon (`;`), which indicates that this
 expression is over and the next one is ready to begin. Most lines of Rust code
 end with a semicolon.
 

rustbook-en/src/ch11-01-writing-tests.md

@@ -62,16 +62,19 @@ cd ../../..
 
 </Listing>
 
+The file starts with an example `add` function, so that we have something
+to test.
+
 For now, let’s focus solely on the `it_works` function. Note the `#[test]`
 annotation: this attribute indicates this is a test function, so the test
 runner knows to treat this function as a test. We might also have non-test
 functions in the `tests` module to help set up common scenarios or perform
 common operations, so we always need to indicate which functions are tests.
 
 The example function body uses the `assert_eq!` macro to assert that `result`,
-which contains the result of adding 2 and 2, equals 4. This assertion serves as
-an example of the format for a typical test. Let’s run it to see that this test
-passes.
+which contains the result of calling `add` with 2 and 2, equals 4. This
+assertion serves as an example of the format for a typical test. Let’s run it
+to see that this test passes.
 
 The `cargo test` command runs all tests in our project, as shown in Listing
 11-2.

rustbook-en/src/ch20-01-unsafe-rust.md

@@ -186,9 +186,14 @@ With the `unsafe` block, we’re asserting to Rust that we’ve read the functio
 documentation, we understand how to use it properly, and we’ve verified that
 we’re fulfilling the contract of the function.
 
-Bodies of unsafe functions are effectively `unsafe` blocks, so to perform other
-unsafe operations within an unsafe function, we don’t need to add another
-`unsafe` block.
+> Note: In earlier versions of Rust, the body of an unsafe function was treated
+> as an `unsafe` block, so you could perform any unsafe operation within the
+> body of an `unsafe` function. In later versions of Rust, the compiler will
+> warn you that you need to use an `unsafe` block to perform unsafe operations
+> in the body of an unsafe function. This is because Rust now distinguishes
+> between `unsafe fn`, which defines what you need to do to call the function
+> safely, and an `unsafe` block, where you actually uphold that “contract” the
+> function establishes.
 
 #### Creating a Safe Abstraction over Unsafe Code
 

rustbook-en/src/ch20-05-advanced-functions-and-closures.md

@@ -95,33 +95,33 @@ function. However, you can’t do that with closures because they don’t have a
 concrete type that is returnable; you’re not allowed to use the function
 pointer `fn` as a return type, for example.
 
-The following code tries to return a closure directly, but it won’t compile:
+Instead, you will normally use the `impl Trait` syntax we learned about in
+Chapter 10. You can return any function type, using `Fn`, `FnOnce` and `FnMut`.
+For example, this code will work just fine:
 
 ```rust,ignore,does_not_compile
 {{#rustdoc_include ../listings/ch20-advanced-features/no-listing-18-returns-closure/src/lib.rs}}
 ```
 
-The compiler error is as follows:
-
-```console
-{{#include ../listings/ch20-advanced-features/no-listing-18-returns-closure/output.txt}}
-```
-
-The error references the `Sized` trait again! Rust doesn’t know how much space
-it will need to store the closure. We saw a solution to this problem earlier.
-We can use a trait object:
+However, as we noted in the [“Closure Type Inference and
+Annotation”][closure-types]<!-- ignore --> section in Chapter 13, each closure
+is also its own distinct type. If you need to work with multiple functions that
+have the same signature but different implementations, you will need to use a
+trait object for them:
 
 ```rust,noplayground
-{{#rustdoc_include ../listings/ch20-advanced-features/no-listing-19-returns-closure-trait-object/src/lib.rs}}
+{{#rustdoc_include ../listings/ch20-advanced-features/no-listing-19-returns-closure-trait-object/src/main.rs}}
 ```
 
-This code will compile just fine. For more about trait objects, refer to the
-section [“Using Trait Objects That Allow for Values of Different
-Types”][using-trait-objects-that-allow-for-values-of-different-types]<!--
-ignore --> in Chapter 19.
+This code will compile just fine—but it wouldn’t if we had tried to stick with
+`impl Fn(i32) -> i32`. For more about trait objects, refer to the section
+[“Using Trait Objects That Allow for Values of Different
+Types”][using-trait-objects-that-allow-for-values-of-different-types]<!-- ignore
+--> in Chapter 19.
 
 Next, let’s look at macros!
 
 [advanced-traits]: ch20-03-advanced-traits.html#advanced-traits
 [enum-values]: ch06-01-defining-an-enum.html#enum-values
+[closure-types]: ch13-01-closures.html#closure-type-inference-and-annotation
 [using-trait-objects-that-allow-for-values-of-different-types]: ch18-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types