Auto merge of rust-lang#116408 - matthiaskrgr:rollup-hmolg4m, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#115961 (Replace 'mutex' with 'lock' in RwLock documentation)
 - rust-lang#116146 (Clarify `arg` and `args` documentation)
 - rust-lang#116363 (Adapt `todo!` documentation to mention displaying custom values)
 - rust-lang#116365 (bootstrap: make copying linker binaries conditional)
 - rust-lang#116388 (rustdoc: fix & clean up handling of cross-crate higher-ranked parameters)
 - rust-lang#116393 (Emit feature gate *warning* for `auto` traits pre-expansion)
 - rust-lang#116395 (Mark myself as vacation or whatever)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

core/src/macros/mod.rs

@@ -719,7 +719,8 @@ macro_rules! unreachable {
 /// The difference between `unimplemented!` and [`todo!`] is that while `todo!`
 /// conveys an intent of implementing the functionality later and the message is "not yet
 /// implemented", `unimplemented!` makes no such claims. Its message is "not implemented".
-/// Also some IDEs will mark `todo!`s.
+///
+/// Also, some IDEs will mark `todo!`s.
 ///
 /// # Panics
 ///
@@ -805,50 +806,63 @@ macro_rules! unimplemented {
 /// The difference between [`unimplemented!`] and `todo!` is that while `todo!` conveys
 /// an intent of implementing the functionality later and the message is "not yet
 /// implemented", `unimplemented!` makes no such claims. Its message is "not implemented".
-/// Also some IDEs will mark `todo!`s.
+///
+/// Also, some IDEs will mark `todo!`s.
 ///
 /// # Panics
 ///
-/// This will always [`panic!`].
+/// This will always [`panic!`] because `todo!` is just a shorthand for `panic!` with a
+/// fixed, specific message.
+///
+/// Like `panic!`, this macro has a second form for displaying custom values.
 ///
 /// # Examples
 ///
 /// Here's an example of some in-progress code. We have a trait `Foo`:
 ///
 /// ```
 /// trait Foo {
-///     fn bar(&self);
+///     fn bar(&self) -> u8;
 ///     fn baz(&self);
+///     fn qux(&self) -> Result<u64, ()>;
 /// }
 /// ```
 ///
 /// We want to implement `Foo` on one of our types, but we also want to work on
 /// just `bar()` first. In order for our code to compile, we need to implement
-/// `baz()`, so we can use `todo!`:
+/// `baz()` and `qux()`, so we can use `todo!`:
 ///
 /// ```
 /// # trait Foo {
-/// #     fn bar(&self);
+/// #     fn bar(&self) -> u8;
 /// #     fn baz(&self);
+/// #     fn qux(&self) -> Result<u64, ()>;
 /// # }
 /// struct MyStruct;
 ///
 /// impl Foo for MyStruct {
-///     fn bar(&self) {
-///         // implementation goes here
+///     fn bar(&self) -> u8 {
+///         1 + 1
 ///     }
 ///
 ///     fn baz(&self) {
-///         // let's not worry about implementing baz() for now
+///         // Let's not worry about implementing baz() for now
 ///         todo!();
 ///     }
+///
+///     fn qux(&self) -> Result<u64, ()> {
+///         // We can add a message to todo! to display our omission.
+///         // This will display:
+///         // "thread 'main' panicked at 'not yet implemented: MyStruct is not yet quxable'".
+///         todo!("MyStruct is not yet quxable");
+///     }
 /// }
 ///
 /// fn main() {
 ///     let s = MyStruct;
 ///     s.bar();
 ///
-///     // we aren't even using baz(), so this is fine.
+///     // We aren't even using baz() or qux(), so this is fine.
 /// }
 /// ```
 #[macro_export]

std/src/process.rs

@@ -607,7 +607,7 @@ impl Command {
     ///
     /// Note that the argument is not passed through a shell, but given
     /// literally to the program. This means that shell syntax like quotes,
-    /// escaped characters, word splitting, glob patterns, substitution, etc.
+    /// escaped characters, word splitting, glob patterns, variable substitution, etc.
     /// have no effect.
     ///
     /// # Examples
@@ -637,7 +637,7 @@ impl Command {
     ///
     /// Note that the arguments are not passed through a shell, but given
     /// literally to the program. This means that shell syntax like quotes,
-    /// escaped characters, word splitting, glob patterns, substitution, etc.
+    /// escaped characters, word splitting, glob patterns, variable substitution, etc.
     /// have no effect.
     ///
     /// # Examples

std/src/sync/rwlock.rs

@@ -380,7 +380,7 @@ impl<T: ?Sized> RwLock<T> {
     ///
     /// If the lock is poisoned, it will remain poisoned until this function is called. This allows
     /// recovering from a poisoned state and marking that it has recovered. For example, if the
-    /// value is overwritten by a known-good value, then the mutex can be marked as un-poisoned. Or
+    /// value is overwritten by a known-good value, then the lock can be marked as un-poisoned. Or
     /// possibly, the value could be inspected to determine if it is in a consistent state, and if
     /// so the poison is removed.
     ///
@@ -397,7 +397,7 @@ impl<T: ?Sized> RwLock<T> {
     ///
     /// let _ = thread::spawn(move || {
     ///     let _lock = c_lock.write().unwrap();
-    ///     panic!(); // the mutex gets poisoned
+    ///     panic!(); // the lock gets poisoned
     /// }).join();
     ///
     /// assert_eq!(lock.is_poisoned(), true);