Merge from rustc

core/src/fmt/mod.rs

@@ -975,9 +975,17 @@ pub trait UpperHex {
 /// `p` formatting.
 ///
 /// The `Pointer` trait should format its output as a memory location. This is commonly presented
-/// as hexadecimal.
+/// as hexadecimal. For more information on formatters, see [the module-level documentation][module].
 ///
-/// For more information on formatters, see [the module-level documentation][module].
+/// Printing of pointers is not a reliable way to discover how Rust programs are implemented.
+/// The act of reading an address changes the program itself, and may change how the data is represented
+/// in memory, and may affect which optimizations are applied to the code.
+///
+/// The printed pointer values are not guaranteed to be stable nor unique identifiers of objects.
+/// Rust allows moving values to different memory locations, and may reuse the same memory locations
+/// for different purposes.
+///
+/// There is no guarantee that the printed value can be converted back to a pointer.
 ///
 /// [module]: ../../std/fmt/index.html
 ///

std/src/process.rs

@@ -1910,10 +1910,14 @@ impl crate::error::Error for ExitStatusError {}
 /// to its parent under normal termination.
 ///
 /// `ExitCode` is intended to be consumed only by the standard library (via
-/// [`Termination::report()`]), and intentionally does not provide accessors like
-/// `PartialEq`, `Eq`, or `Hash`. Instead the standard library provides the
-/// canonical `SUCCESS` and `FAILURE` exit codes as well as `From<u8> for
-/// ExitCode` for constructing other arbitrary exit codes.
+/// [`Termination::report()`]). For forwards compatibility with potentially
+/// unusual targets, this type currently does not provide `Eq`, `Hash`, or
+/// access to the raw value. This type does provide `PartialEq` for
+/// comparison, but note that there may potentially be multiple failure
+/// codes, some of which will _not_ compare equal to `ExitCode::FAILURE`.
+/// The standard library provides the canonical `SUCCESS` and `FAILURE`
+/// exit codes as well as `From<u8> for ExitCode` for constructing other
+/// arbitrary exit codes.
 ///
 /// # Portability
 ///
@@ -1952,7 +1956,7 @@ impl crate::error::Error for ExitStatusError {}
 ///     ExitCode::SUCCESS
 /// }
 /// ```
-#[derive(Clone, Copy, Debug)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 #[stable(feature = "process_exitcode", since = "1.61.0")]
 pub struct ExitCode(imp::ExitCode);