Rollup merge of rust-lang#106860 - anden3:doc-double-spaces, r=Dylan-DPC

Remove various double spaces in the libraries.

I was just pretty bothered by this when reading the source for a function, and was suggested to check if this happened elsewhere.

Author: matthiaskrgr

library/alloc/src/alloc.rs

@@ -20,7 +20,7 @@ use core::marker::Destruct;
 mod tests;
 
 extern "Rust" {
-    // These are the magic symbols to call the global allocator.  rustc generates
+    // These are the magic symbols to call the global allocator. rustc generates
     // them to call `__rg_alloc` etc. if there is a `#[global_allocator]` attribute
     // (the code expanding that attribute macro generates those functions), or to call
     // the default implementations in std (`__rdl_alloc` etc. in `library/std/src/alloc.rs`)
@@ -353,7 +353,7 @@ pub(crate) const unsafe fn box_free<T: ?Sized, A: ~const Allocator + ~const Dest
 
 #[cfg(not(no_global_oom_handling))]
 extern "Rust" {
-    // This is the magic symbol to call the global alloc error handler.  rustc generates
+    // This is the magic symbol to call the global alloc error handler. rustc generates
     // it to call `__rg_oom` if there is a `#[alloc_error_handler]`, or to call the
     // default implementations below (`__rdl_oom`) otherwise.
     fn __rust_alloc_error_handler(size: usize, align: usize) -> !;

library/alloc/src/rc.rs

@@ -2179,7 +2179,7 @@ pub struct Weak<T: ?Sized> {
     // This is a `NonNull` to allow optimizing the size of this type in enums,
     // but it is not necessarily a valid pointer.
     // `Weak::new` sets this to `usize::MAX` so that it doesn’t need
-    // to allocate space on the heap.  That's not a value a real pointer
+    // to allocate space on the heap. That's not a value a real pointer
     // will ever have because RcBox has alignment at least 2.
     // This is only possible when `T: Sized`; unsized `T` never dangle.
     ptr: NonNull<RcBox<T>>,

library/alloc/src/sync.rs

@@ -295,7 +295,7 @@ pub struct Weak<T: ?Sized> {
     // This is a `NonNull` to allow optimizing the size of this type in enums,
     // but it is not necessarily a valid pointer.
     // `Weak::new` sets this to `usize::MAX` so that it doesn’t need
-    // to allocate space on the heap.  That's not a value a real pointer
+    // to allocate space on the heap. That's not a value a real pointer
     // will ever have because RcBox has alignment at least 2.
     // This is only possible when `T: Sized`; unsized `T` never dangle.
     ptr: NonNull<ArcInner<T>>,
@@ -1656,7 +1656,7 @@ impl<T: ?Sized> Arc<T> {
         //
         // The acquire label here ensures a happens-before relationship with any
         // writes to `strong` (in particular in `Weak::upgrade`) prior to decrements
-        // of the `weak` count (via `Weak::drop`, which uses release).  If the upgraded
+        // of the `weak` count (via `Weak::drop`, which uses release). If the upgraded
         // weak ref was never dropped, the CAS here will fail so we do not care to synchronize.
         if self.inner().weak.compare_exchange(1, usize::MAX, Acquire, Relaxed).is_ok() {
             // This needs to be an `Acquire` to synchronize with the decrement of the `strong`
@@ -1712,7 +1712,7 @@ unsafe impl<#[may_dangle] T: ?Sized> Drop for Arc<T> {
         }
 
         // This fence is needed to prevent reordering of use of the data and
-        // deletion of the data.  Because it is marked `Release`, the decreasing
+        // deletion of the data. Because it is marked `Release`, the decreasing
         // of the reference count synchronizes with this `Acquire` fence. This
         // means that use of the data happens before decreasing the reference
         // count, which happens before this fence, which happens before the
@@ -2172,7 +2172,7 @@ impl<T: ?Sized> Clone for Weak<T> {
         } else {
             return Weak { ptr: self.ptr };
         };
-        // See comments in Arc::clone() for why this is relaxed.  This can use a
+        // See comments in Arc::clone() for why this is relaxed. This can use a
         // fetch_add (ignoring the lock) because the weak count is only locked
         // where are *no other* weak pointers in existence. (So we can't be
         // running this code in that case).

library/alloc/src/vec/into_iter.rs

@@ -40,7 +40,7 @@ pub struct IntoIter<
     // to avoid dropping the allocator twice we need to wrap it into ManuallyDrop
     pub(super) alloc: ManuallyDrop<A>,
     pub(super) ptr: *const T,
-    pub(super) end: *const T, // If T is a ZST, this is actually ptr+len.  This encoding is picked so that
+    pub(super) end: *const T, // If T is a ZST, this is actually ptr+len. This encoding is picked so that
                               // ptr == end is a quick test for the Iterator being empty, that works
                               // for both ZST and non-ZST.
 }
@@ -146,9 +146,9 @@ impl<T, A: Allocator> IntoIter<T, A> {
         let mut this = ManuallyDrop::new(self);
 
         // SAFETY: This allocation originally came from a `Vec`, so it passes
-        // all those checks.  We have `this.buf` ≤ `this.ptr` ≤ `this.end`,
+        // all those checks. We have `this.buf` ≤ `this.ptr` ≤ `this.end`,
         // so the `sub_ptr`s below cannot wrap, and will produce a well-formed
-        // range.  `end` ≤ `buf + cap`, so the range will be in-bounds.
+        // range. `end` ≤ `buf + cap`, so the range will be in-bounds.
         // Taking `alloc` is ok because nothing else is going to look at it,
         // since our `Drop` impl isn't going to run so there's no more code.
         unsafe {

library/alloc/src/vec/is_zero.rs

@@ -57,7 +57,7 @@ unsafe impl<T: IsZero, const N: usize> IsZero for [T; N] {
     #[inline]
     fn is_zero(&self) -> bool {
         // Because this is generated as a runtime check, it's not obvious that
-        // it's worth doing if the array is really long.  The threshold here
+        // it's worth doing if the array is really long. The threshold here
         // is largely arbitrary, but was picked because as of 2022-07-01 LLVM
         // fails to const-fold the check in `vec![[1; 32]; n]`
         // See https://github.com/rust-lang/rust/pull/97581#issuecomment-1166628022

library/alloc/src/vec/mod.rs

@@ -2429,7 +2429,7 @@ impl<T: Clone, A: Allocator> Vec<T, A> {
         self.reserve(range.len());
 
         // SAFETY:
-        // - `slice::range` guarantees  that the given range is valid for indexing self
+        // - `slice::range` guarantees that the given range is valid for indexing self
         unsafe {
             self.spec_extend_from_within(range);
         }
@@ -2686,7 +2686,7 @@ impl<T: Clone, A: Allocator + Clone> Clone for Vec<T, A> {
 
     // HACK(japaric): with cfg(test) the inherent `[T]::to_vec` method, which is
     // required for this method definition, is not available. Instead use the
-    // `slice::to_vec`  function which is only available with cfg(test)
+    // `slice::to_vec` function which is only available with cfg(test)
     // NB see the slice::hack module in slice.rs for more information
     #[cfg(test)]
     fn clone(&self) -> Self {

library/alloc/tests/vec.rs

@@ -1849,7 +1849,7 @@ fn test_stable_pointers() {
     }
 
     // Test that, if we reserved enough space, adding and removing elements does not
-    // invalidate references into the vector (such as `v0`).  This test also
+    // invalidate references into the vector (such as `v0`). This test also
     // runs in Miri, which would detect such problems.
     // Note that this test does *not* constitute a stable guarantee that all these functions do not
     // reallocate! Only what is explicitly documented at

library/core/src/array/iter.rs

@@ -109,8 +109,8 @@ impl<T, const N: usize> IntoIter<T, N> {
     /// use std::array::IntoIter;
     /// use std::mem::MaybeUninit;
     ///
-    /// # // Hi!  Thanks for reading the code.  This is restricted to `Copy` because
-    /// # // otherwise it could leak.  A fully-general version this would need a drop
+    /// # // Hi!  Thanks for reading the code. This is restricted to `Copy` because
+    /// # // otherwise it could leak. A fully-general version this would need a drop
     /// # // guard to handle panics from the iterator, but this works for an example.
     /// fn next_chunk<T: Copy, const N: usize>(
     ///     it: &mut impl Iterator<Item = T>,
@@ -211,7 +211,7 @@ impl<T, const N: usize> IntoIter<T, N> {
         let initialized = 0..0;
 
         // SAFETY: We're telling it that none of the elements are initialized,
-        // which is trivially true.  And ∀N: usize, 0 <= N.
+        // which is trivially true. And ∀N: usize, 0 <= N.
         unsafe { Self::new_unchecked(buffer, initialized) }
     }
 

library/core/src/iter/range.rs

@@ -756,7 +756,7 @@ impl<A: Step> Iterator for ops::Range<A> {
     where
         Self: TrustedRandomAccessNoCoerce,
     {
-        // SAFETY: The TrustedRandomAccess contract requires that callers only  pass an index
+        // SAFETY: The TrustedRandomAccess contract requires that callers only pass an index
         // that is in bounds.
         // Additionally Self: TrustedRandomAccess is only implemented for Copy types
         // which means even repeated reads of the same index would be safe.

library/core/src/num/dec2flt/fpu.rs

@@ -26,7 +26,7 @@ mod fpu_precision {
     /// Developer's Manual (Volume 1).
     ///
     /// The only field which is relevant for the following code is PC, Precision Control. This
-    /// field determines the precision of the operations performed by the  FPU. It can be set to:
+    /// field determines the precision of the operations performed by the FPU. It can be set to:
     ///  - 0b00, single precision i.e., 32-bits
     ///  - 0b10, double precision i.e., 64-bits
     ///  - 0b11, double extended precision i.e., 80-bits (default state)

library/core/src/num/int_macros.rs

@@ -1538,7 +1538,7 @@ macro_rules! int_impl {
         ///
         /// ```
         /// #![feature(bigint_helper_methods)]
-        /// // Only the  most significant word is signed.
+        /// // Only the most significant word is signed.
         /// //
         #[doc = concat!("//   10  MAX    (a = 10 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")]
         #[doc = concat!("// + -5    9    (b = -5 × 2^", stringify!($BITS), " + 9)")]
@@ -1646,7 +1646,7 @@ macro_rules! int_impl {
         ///
         /// ```
         /// #![feature(bigint_helper_methods)]
-        /// // Only the  most significant word is signed.
+        /// // Only the most significant word is signed.
         /// //
         #[doc = concat!("//    6    8    (a = 6 × 2^", stringify!($BITS), " + 8)")]
         #[doc = concat!("// - -5    9    (b = -5 × 2^", stringify!($BITS), " + 9)")]

library/core/src/pin.rs

@@ -753,7 +753,7 @@ impl<P: DerefMut> Pin<P> {
 impl<'a, T: ?Sized> Pin<&'a T> {
     /// Constructs a new pin by mapping the interior value.
     ///
-    /// For example, if you  wanted to get a `Pin` of a field of something,
+    /// For example, if you wanted to get a `Pin` of a field of something,
     /// you could use this to get access to that field in one line of code.
     /// However, there are several gotchas with these "pinning projections";
     /// see the [`pin` module] documentation for further details on that topic.
@@ -856,7 +856,7 @@ impl<'a, T: ?Sized> Pin<&'a mut T> {
 
     /// Construct a new pin by mapping the interior value.
     ///
-    /// For example, if you  wanted to get a `Pin` of a field of something,
+    /// For example, if you wanted to get a `Pin` of a field of something,
     /// you could use this to get access to that field in one line of code.
     /// However, there are several gotchas with these "pinning projections";
     /// see the [`pin` module] documentation for further details on that topic.

library/core/src/ptr/mod.rs

@@ -1701,7 +1701,7 @@ pub(crate) const unsafe fn align_offset<T: Sized>(p: *const T, a: usize) -> usiz
         // offset is not a multiple of `stride`, the input pointer was misaligned and no pointer
         // offset will be able to produce a `p` aligned to the specified `a`.
         //
-        // The naive `-p (mod a)` equation  inhibits LLVM's ability to select instructions
+        // The naive `-p (mod a)` equation inhibits LLVM's ability to select instructions
         // like `lea`. We compute `(round_up_to_next_alignment(p, a) - p)` instead. This
         // redistributes operations around the load-bearing, but pessimizing `and` instruction
         // sufficiently for LLVM to be able to utilize the various optimizations it knows about.

library/core/src/slice/iter.rs

@@ -65,7 +65,7 @@ fn size_from_ptr<T>(_: *const T) -> usize {
 #[must_use = "iterators are lazy and do nothing unless consumed"]
 pub struct Iter<'a, T: 'a> {
     ptr: NonNull<T>,
-    end: *const T, // If T is a ZST, this is actually ptr+len.  This encoding is picked so that
+    end: *const T, // If T is a ZST, this is actually ptr+len. This encoding is picked so that
     // ptr == end is a quick test for the Iterator being empty, that works
     // for both ZST and non-ZST.
     _marker: PhantomData<&'a T>,
@@ -186,7 +186,7 @@ impl<T> AsRef<[T]> for Iter<'_, T> {
 #[must_use = "iterators are lazy and do nothing unless consumed"]
 pub struct IterMut<'a, T: 'a> {
     ptr: NonNull<T>,
-    end: *mut T, // If T is a ZST, this is actually ptr+len.  This encoding is picked so that
+    end: *mut T, // If T is a ZST, this is actually ptr+len. This encoding is picked so that
     // ptr == end is a quick test for the Iterator being empty, that works
     // for both ZST and non-ZST.
     _marker: PhantomData<&'a mut T>,

library/core/src/slice/iter/macros.rs

@@ -23,7 +23,7 @@ macro_rules! len {
             $self.end.addr().wrapping_sub(start.as_ptr().addr())
         } else {
             // We know that `start <= end`, so can do better than `offset_from`,
-            // which needs to deal in signed.  By setting appropriate flags here
+            // which needs to deal in signed. By setting appropriate flags here
             // we can tell LLVM this, which helps it remove bounds checks.
             // SAFETY: By the type invariant, `start <= end`
             let diff = unsafe { unchecked_sub($self.end.addr(), start.as_ptr().addr()) };

library/core/src/slice/mod.rs

@@ -703,7 +703,7 @@ impl<T> [T] {
 
             // Because this function is first compiled in isolation,
             // this check tells LLVM that the indexing below is
-            // in-bounds.  Then after inlining -- once the actual
+            // in-bounds. Then after inlining -- once the actual
             // lengths of the slices are known -- it's removed.
             let (a, b) = (&mut a[..n], &mut b[..n]);
 
@@ -1248,7 +1248,7 @@ impl<T> [T] {
         ArrayChunksMut::new(self)
     }
 
-    /// Returns an iterator over overlapping windows of `N` elements of  a slice,
+    /// Returns an iterator over overlapping windows of `N` elements of a slice,
     /// starting at the beginning of the slice.
     ///
     /// This is the const generic equivalent of [`windows`].
@@ -2476,7 +2476,7 @@ impl<T> [T] {
             let mid = left + size / 2;
 
             // SAFETY: the while condition means `size` is strictly positive, so
-            // `size/2 < size`.  Thus `left + size/2 < left + size`, which
+            // `size/2 < size`. Thus `left + size/2 < left + size`, which
             // coupled with the `left + size <= self.len()` invariant means
             // we have `left + size/2 < self.len()`, and this is in-bounds.
             let cmp = f(unsafe { self.get_unchecked(mid) });

library/core/src/slice/sort.rs

@@ -18,9 +18,9 @@ struct CopyOnDrop<T> {
 
 impl<T> Drop for CopyOnDrop<T> {
     fn drop(&mut self) {
-        // SAFETY:  This is a helper class.
-        //          Please refer to its usage for correctness.
-        //          Namely, one must be sure that `src` and `dst` does not overlap as required by `ptr::copy_nonoverlapping`.
+        // SAFETY: This is a helper class.
+        //         Please refer to its usage for correctness.
+        //         Namely, one must be sure that `src` and `dst` does not overlap as required by `ptr::copy_nonoverlapping`.
         unsafe {
             ptr::copy_nonoverlapping(self.src, self.dest, 1);
         }

library/core/tests/slice.rs

@@ -1488,7 +1488,7 @@ mod slice_index {
                 // optional:
                 //
                 // one or more similar inputs for which data[input] succeeds,
-                // and the corresponding output as an array.  This helps validate
+                // and the corresponding output as an array. This helps validate
                 // "critical points" where an input range straddles the boundary
                 // between valid and invalid.
                 // (such as the input `len..len`, which is just barely valid)

library/std/src/fs.rs

@@ -1512,7 +1512,7 @@ impl FileType {
     }
 
     /// Tests whether this file type represents a regular file.
-    /// The result is  mutually exclusive to the results of
+    /// The result is mutually exclusive to the results of
     /// [`is_dir`] and [`is_symlink`]; only zero or one of these
     /// tests may pass.
     ///

library/std/src/io/buffered/tests.rs

@@ -288,8 +288,8 @@ fn test_buffered_reader_seek_underflow_discard_buffer_between_seeks() {
     let mut reader = BufReader::with_capacity(5, ErrAfterFirstSeekReader { first_seek: true });
     assert_eq!(reader.fill_buf().ok(), Some(&[0, 0, 0, 0, 0][..]));
 
-    // The following seek will require two underlying seeks.  The first will
-    // succeed but the second will fail.  This should still invalidate the
+    // The following seek will require two underlying seeks. The first will
+    // succeed but the second will fail. This should still invalidate the
     // buffer.
     assert!(reader.seek(SeekFrom::Current(i64::MIN)).is_err());
     assert_eq!(reader.buffer().len(), 0);

library/std/src/os/fd/owned.rs

@@ -100,7 +100,7 @@ impl BorrowedFd<'_> {
 
         // For ESP-IDF, F_DUPFD is used instead, because the CLOEXEC semantics
         // will never be supported, as this is a bare metal framework with
-        // no capabilities for multi-process execution.  While F_DUPFD is also
+        // no capabilities for multi-process execution. While F_DUPFD is also
         // not supported yet, it might be (currently it returns ENOSYS).
         #[cfg(target_os = "espidf")]
         let cmd = libc::F_DUPFD;

library/std/src/panicking.rs

@@ -306,11 +306,11 @@ pub mod panic_count {
     // and after increase and decrease, but not necessarily during their execution.
     //
     // Additionally, the top bit of GLOBAL_PANIC_COUNT (GLOBAL_ALWAYS_ABORT_FLAG)
-    // records whether panic::always_abort() has been called.  This can only be
+    // records whether panic::always_abort() has been called. This can only be
     // set, never cleared.
     // panic::always_abort() is usually called to prevent memory allocations done by
     // the panic handling in the child created by `libc::fork`.
-    // Memory allocations performed in  a child created with `libc::fork` are undefined
+    // Memory allocations performed in a child created with `libc::fork` are undefined
     // behavior in most operating systems.
     // Accessing LOCAL_PANIC_COUNT in a child created by `libc::fork` would lead to a memory
     // allocation. Only GLOBAL_PANIC_COUNT can be accessed in this situation. This is

library/std/src/path.rs

@@ -607,7 +607,7 @@ pub struct Components<'a> {
 
     // true if path *physically* has a root separator; for most Windows
     // prefixes, it may have a "logical" root separator for the purposes of
-    // normalization, e.g.,  \\server\share == \\server\share\.
+    // normalization, e.g., \\server\share == \\server\share\.
     has_physical_root: bool,
 
     // The iterator is double-ended, and these two states keep track of what has

library/std/src/sys/itron/thread.rs

@@ -294,7 +294,7 @@ impl Drop for Thread {
                 // Terminate and delete the task
                 // Safety: `self.task` still represents a task we own (because
                 //         this method or `join_inner` is called only once for
-                //         each `Thread`). The task  indicated that it's safe to
+                //         each `Thread`). The task indicated that it's safe to
                 //         delete by entering the `FINISHED` state.
                 unsafe { terminate_and_delete_task(self.task) };