A few cosmetic improvements to code & comments in liballoc and libcore

src/liballoc/collections/linked_list/tests.rs

@@ -102,8 +102,8 @@ fn test_append() {
         assert_eq!(m.pop_front(), Some(elt))
     }
     assert_eq!(n.len(), 0);
-    // let's make sure it's working properly, since we
+    // Let's make sure it's working properly, since we
-    // did some direct changes to private members
+    // did some direct changes to private members.
     n.push_back(3);
     assert_eq!(n.len(), 1);
     assert_eq!(n.pop_front(), Some(3));

src/liballoc/raw_vec.rs

@@ -19,26 +19,26 @@ mod tests;
 /// involved. This type is excellent for building your own data structures like Vec and VecDeque.
 /// In particular:
 ///
-/// * Produces Unique::empty() on zero-sized types
+/// * Produces `Unique::empty()` on zero-sized types.
-/// * Produces Unique::empty() on zero-length allocations
+/// * Produces `Unique::empty()` on zero-length allocations.
-/// * Catches all overflows in capacity computations (promotes them to "capacity overflow" panics)
+/// * Catches all overflows in capacity computations (promotes them to "capacity overflow" panics).
-/// * Guards against 32-bit systems allocating more than isize::MAX bytes
+/// * Guards against 32-bit systems allocating more than isize::MAX bytes.
-/// * Guards against overflowing your length
+/// * Guards against overflowing your length.
-/// * Aborts on OOM or calls handle_alloc_error as applicable
+/// * Aborts on OOM or calls `handle_alloc_error` as applicable.
-/// * Avoids freeing Unique::empty()
+/// * Avoids freeing `Unique::empty()`.
-/// * Contains a ptr::Unique and thus endows the user with all related benefits
+/// * Contains a `ptr::Unique` and thus endows the user with all related benefits.
 ///
 /// This type does not in anyway inspect the memory that it manages. When dropped it *will*
-/// free its memory, but it *won't* try to Drop its contents. It is up to the user of RawVec
+/// free its memory, but it *won't* try to drop its contents. It is up to the user of `RawVec`
-/// to handle the actual things *stored* inside of a RawVec.
+/// to handle the actual things *stored* inside of a `RawVec`.
 ///
-/// Note that a RawVec always forces its capacity to be usize::MAX for zero-sized types.
+/// Note that a `RawVec` always forces its capacity to be `usize::MAX` for zero-sized types.
-/// This enables you to use capacity growing logic catch the overflows in your length
+/// This enables you to use capacity-growing logic catch the overflows in your length
 /// that might occur with zero-sized types.
 ///
-/// However this means that you need to be careful when round-tripping this type
+/// The above means that you need to be careful when round-tripping this type with a
-/// with a `Box<[T]>`: `capacity()` won't yield the len. However `with_capacity`,
+/// `Box<[T]>`, since `capacity()` won't yield the length. However, `with_capacity`,
-/// `shrink_to_fit`, and `from_box` will actually set RawVec's private capacity
+/// `shrink_to_fit`, and `from_box` will actually set `RawVec`'s private capacity
 /// field. This allows zero-sized types to not be special-cased by consumers of
 /// this type.
 #[allow(missing_debug_implementations)]
@@ -49,14 +49,14 @@ pub struct RawVec<T, A: Alloc = Global> {
 }
 
 impl<T, A: Alloc> RawVec<T, A> {
-    /// Like `new` but parameterized over the choice of allocator for
+    /// Like `new`, but parameterized over the choice of allocator for
-    /// the returned RawVec.
+    /// the returned `RawVec`.
     pub const fn new_in(a: A) -> Self {
-        // !0 is usize::MAX. This branch should be stripped at compile time.
+        // `!0` is `usize::MAX`. This branch should be stripped at compile time.
-        // FIXME(mark-i-m): use this line when `if`s are allowed in `const`
+        // FIXME(mark-i-m): use this line when `if`s are allowed in `const`:
         //let cap = if mem::size_of::<T>() == 0 { !0 } else { 0 };
 
-        // Unique::empty() doubles as "unallocated" and "zero-sized allocation"
+        // `Unique::empty()` doubles as "unallocated" and "zero-sized allocation".
         RawVec {
             ptr: Unique::empty(),
             // FIXME(mark-i-m): use `cap` when ifs are allowed in const
@@ -65,15 +65,15 @@ impl<T, A: Alloc> RawVec<T, A> {
         }
     }
 
-    /// Like `with_capacity` but parameterized over the choice of
+    /// Like `with_capacity`, but parameterized over the choice of
-    /// allocator for the returned RawVec.
+    /// allocator for the returned `RawVec`.
     #[inline]
     pub fn with_capacity_in(capacity: usize, a: A) -> Self {
         RawVec::allocate_in(capacity, false, a)
     }
 
-    /// Like `with_capacity_zeroed` but parameterized over the choice
+    /// Like `with_capacity_zeroed`, but parameterized over the choice
-    /// of allocator for the returned RawVec.
+    /// of allocator for the returned `RawVec`.
     #[inline]
     pub fn with_capacity_zeroed_in(capacity: usize, a: A) -> Self {
         RawVec::allocate_in(capacity, true, a)
@@ -86,7 +86,7 @@ impl<T, A: Alloc> RawVec<T, A> {
             let alloc_size = capacity.checked_mul(elem_size).unwrap_or_else(|| capacity_overflow());
             alloc_guard(alloc_size).unwrap_or_else(|_| capacity_overflow());
 
-            // handles ZSTs and `capacity = 0` alike
+            // Handles ZSTs and `capacity == 0` alike.
             let ptr = if alloc_size == 0 {
                 NonNull::<T>::dangling()
             } else {
@@ -113,20 +113,20 @@ impl<T, A: Alloc> RawVec<T, A> {
 }
 
 impl<T> RawVec<T, Global> {
-    /// Creates the biggest possible RawVec (on the system heap)
+    /// Creates the biggest possible `RawVec` (on the system heap)
-    /// without allocating. If T has positive size, then this makes a
+    /// without allocating. If `T` has positive size, then this makes a
-    /// RawVec with capacity 0. If T has 0 size, then it makes a
+    /// `RawVec` with capacity `0`. If `T` is zero-sized, then it makes a
-    /// RawVec with capacity `usize::MAX`. Useful for implementing
+    /// `RawVec` with capacity `usize::MAX`. Useful for implementing
     /// delayed allocation.
     pub const fn new() -> Self {
         Self::new_in(Global)
     }
 
-    /// Creates a RawVec (on the system heap) with exactly the
+    /// Creates a `RawVec` (on the system heap) with exactly the
     /// capacity and alignment requirements for a `[T; capacity]`. This is
-    /// equivalent to calling RawVec::new when `capacity` is 0 or T is
+    /// equivalent to calling `RawVec::new` when `capacity` is `0` or `T` is
     /// zero-sized. Note that if `T` is zero-sized this means you will
-    /// *not* get a RawVec with the requested capacity!
+    /// *not* get a `RawVec` with the requested capacity.
     ///
     /// # Panics
     ///
@@ -136,13 +136,13 @@ impl<T> RawVec<T, Global> {
     ///
     /// # Aborts
     ///
-    /// Aborts on OOM
+    /// Aborts on OOM.
     #[inline]
     pub fn with_capacity(capacity: usize) -> Self {
         RawVec::allocate_in(capacity, false, Global)
     }
 
-    /// Like `with_capacity` but guarantees the buffer is zeroed.
+    /// Like `with_capacity`, but guarantees the buffer is zeroed.
     #[inline]
     pub fn with_capacity_zeroed(capacity: usize) -> Self {
         RawVec::allocate_in(capacity, true, Global)
@@ -150,13 +150,13 @@ impl<T> RawVec<T, Global> {
 }
 
 impl<T, A: Alloc> RawVec<T, A> {
-    /// Reconstitutes a RawVec from a pointer, capacity, and allocator.
+    /// Reconstitutes a `RawVec` from a pointer, capacity, and allocator.
     ///
     /// # Undefined Behavior
     ///
-    /// The ptr must be allocated (via the given allocator `a`), and with the given capacity. The
+    /// The `ptr` must be allocated (via the given allocator `a`), and with the given `capacity`.
-    /// capacity cannot exceed `isize::MAX` (only a concern on 32-bit systems).
+    /// The `capacity` cannot exceed `isize::MAX` (only a concern on 32-bit systems).
-    /// If the ptr and capacity come from a RawVec created via `a`, then this is guaranteed.
+    /// If the `ptr` and `capacity` come from a `RawVec` created via `a`, then this is guaranteed.
     pub unsafe fn from_raw_parts_in(ptr: *mut T, capacity: usize, a: A) -> Self {
         RawVec {
             ptr: Unique::new_unchecked(ptr),
@@ -167,13 +167,13 @@ impl<T, A: Alloc> RawVec<T, A> {
 }
 
 impl<T> RawVec<T, Global> {
-    /// Reconstitutes a RawVec from a pointer, capacity.
+    /// Reconstitutes a `RawVec` from a pointer and capacity.
     ///
     /// # Undefined Behavior
     ///
-    /// The ptr must be allocated (on the system heap), and with the given capacity. The
+    /// The `ptr` must be allocated (on the system heap), and with the given `capacity`.
-    /// capacity cannot exceed `isize::MAX` (only a concern on 32-bit systems).
+    /// Th `capacity` cannot exceed `isize::MAX` (only a concern on 32-bit systems).
-    /// If the ptr and capacity come from a RawVec, then this is guaranteed.
+    /// If the `ptr` and `capacity` come from a `RawVec`, then this is guaranteed.
     pub unsafe fn from_raw_parts(ptr: *mut T, capacity: usize) -> Self {
         RawVec {
             ptr: Unique::new_unchecked(ptr),
@@ -194,7 +194,7 @@ impl<T> RawVec<T, Global> {
 
 impl<T, A: Alloc> RawVec<T, A> {
     /// Gets a raw pointer to the start of the allocation. Note that this is
-    /// Unique::empty() if `capacity = 0` or T is zero-sized. In the former case, you must
+    /// `Unique::empty()` if `capacity == 0` or `T` is zero-sized. In the former case, you must
     /// be careful.
     pub fn ptr(&self) -> *mut T {
         self.ptr.as_ptr()
@@ -212,12 +212,12 @@ impl<T, A: Alloc> RawVec<T, A> {
         }
     }
 
-    /// Returns a shared reference to the allocator backing this RawVec.
+    /// Returns a shared reference to the allocator backing this `RawVec`.
     pub fn alloc(&self) -> &A {
         &self.a
     }
 
-    /// Returns a mutable reference to the allocator backing this RawVec.
+    /// Returns a mutable reference to the allocator backing this `RawVec`.
     pub fn alloc_mut(&mut self) -> &mut A {
         &mut self.a
     }
@@ -247,7 +247,7 @@ impl<T, A: Alloc> RawVec<T, A> {
     ///
     /// # Panics
     ///
-    /// * Panics if T is zero-sized on the assumption that you managed to exhaust
+    /// * Panics if `T` is zero-sized on the assumption that you managed to exhaust
     ///   all `usize::MAX` slots in your imaginary buffer.
     /// * Panics on 32-bit platforms if the requested capacity exceeds
     ///   `isize::MAX` bytes.
@@ -290,20 +290,20 @@ impl<T, A: Alloc> RawVec<T, A> {
         unsafe {
             let elem_size = mem::size_of::<T>();
 
-            // since we set the capacity to usize::MAX when elem_size is
+            // Since we set the capacity to `usize::MAX` when `elem_size` is
-            // 0, getting to here necessarily means the RawVec is overfull.
+            // 0, getting to here necessarily means the `RawVec` is overfull.
             assert!(elem_size != 0, "capacity overflow");
 
             let (new_cap, uniq) = match self.current_layout() {
                 Some(cur) => {
                     // Since we guarantee that we never allocate more than
-                    // isize::MAX bytes, `elem_size * self.cap <= isize::MAX` as
+                    // `isize::MAX` bytes, `elem_size * self.cap <= isize::MAX` as
                     // a precondition, so this can't overflow. Additionally the
                     // alignment will never be too large as to "not be
                     // satisfiable", so `Layout::from_size_align` will always
                     // return `Some`.
                     //
-                    // tl;dr; we bypass runtime checks due to dynamic assertions
+                    // TL;DR, we bypass runtime checks due to dynamic assertions
                     // in this module, allowing us to use
                     // `from_size_align_unchecked`.
                     let new_cap = 2 * self.cap;
@@ -320,8 +320,8 @@ impl<T, A: Alloc> RawVec<T, A> {
                     }
                 }
                 None => {
-                    // skip to 4 because tiny Vec's are dumb; but not if that
+                    // Skip to 4 because tiny `Vec`'s are dumb; but not if that
-                    // would cause overflow
+                    // would cause overflow.
                     let new_cap = if elem_size > (!0) / 8 { 1 } else { 4 };
                     match self.a.alloc_array::<T>(new_cap) {
                         Ok(ptr) => (new_cap, ptr.into()),
@@ -342,7 +342,7 @@ impl<T, A: Alloc> RawVec<T, A> {
     ///
     /// # Panics
     ///
-    /// * Panics if T is zero-sized on the assumption that you managed to exhaust
+    /// * Panics if `T` is zero-sized on the assumption that you managed to exhaust
     ///   all `usize::MAX` slots in your imaginary buffer.
     /// * Panics on 32-bit platforms if the requested capacity exceeds
     ///   `isize::MAX` bytes.
@@ -356,15 +356,15 @@ impl<T, A: Alloc> RawVec<T, A> {
                 None => return false, // nothing to double
             };
 
-            // since we set the capacity to usize::MAX when elem_size is
+            // Since we set the capacity to `usize::MAX` when `elem_size` is
-            // 0, getting to here necessarily means the RawVec is overfull.
+            // 0, getting to here necessarily means the `RawVec` is overfull.
             assert!(elem_size != 0, "capacity overflow");
 
-            // Since we guarantee that we never allocate more than isize::MAX
+            // Since we guarantee that we never allocate more than `isize::MAX`
             // bytes, `elem_size * self.cap <= isize::MAX` as a precondition, so
             // this can't overflow.
             //
-            // Similarly like with `double` above we can go straight to
+            // Similarly to with `double` above, we can go straight to
             // `Layout::from_size_align_unchecked` as we know this won't
             // overflow and the alignment is sufficiently small.
             let new_cap = 2 * self.cap;
@@ -409,7 +409,7 @@ impl<T, A: Alloc> RawVec<T, A> {
     ///
     /// # Aborts
     ///
-    /// Aborts on OOM
+    /// Aborts on OOM.
     pub fn reserve_exact(&mut self, used_capacity: usize, needed_extra_capacity: usize) {
         match self.reserve_internal(used_capacity, needed_extra_capacity, Infallible, Exact) {
             Err(CapacityOverflow) => capacity_overflow(),
@@ -424,7 +424,7 @@ impl<T, A: Alloc> RawVec<T, A> {
     fn amortized_new_size(&self, used_capacity: usize, needed_extra_capacity: usize)
         -> Result<usize, TryReserveError> {
 
-        // Nothing we can really do about these checks :(
+        // Nothing we can really do about these checks, sadly.
         let required_cap = used_capacity.checked_add(needed_extra_capacity)
             .ok_or(CapacityOverflow)?;
         // Cannot overflow, because `cap <= isize::MAX`, and type of `cap` is `usize`.
@@ -459,7 +459,7 @@ impl<T, A: Alloc> RawVec<T, A> {
     ///
     /// # Aborts
     ///
-    /// Aborts on OOM
+    /// Aborts on OOM.
     ///
     /// # Examples
     ///
@@ -538,7 +538,7 @@ impl<T, A: Alloc> RawVec<T, A> {
 
             // Here, `cap < used_capacity + needed_extra_capacity <= new_cap`
             // (regardless of whether `self.cap - used_capacity` wrapped).
-            // Therefore we can safely call grow_in_place.
+            // Therefore, we can safely call `grow_in_place`.
 
             let new_layout = Layout::new::<T>().repeat(new_cap).unwrap().0;
             // FIXME: may crash and burn on over-reserve
@@ -576,14 +576,14 @@ impl<T, A: Alloc> RawVec<T, A> {
             return;
         }
 
-        // This check is my waterloo; it's the only thing Vec wouldn't have to do.
+        // This check is my waterloo; it's the only thing `Vec` wouldn't have to do.
         assert!(self.cap >= amount, "Tried to shrink to a larger capacity");
 
         if amount == 0 {
             // We want to create a new zero-length vector within the
-            // same allocator.  We use ptr::write to avoid an
+            // same allocator. We use `ptr::write` to avoid an
             // erroneous attempt to drop the contents, and we use
-            // ptr::read to sidestep condition against destructuring
+            // `ptr::read` to sidestep condition against destructuring
             // types that implement Drop.
 
             unsafe {
@@ -600,7 +600,7 @@ impl<T, A: Alloc> RawVec<T, A> {
                 //
                 // We also know that `self.cap` is greater than `amount`, and
                 // consequently we don't need runtime checks for creating either
-                // layout
+                // layout.
                 let old_size = elem_size * self.cap;
                 let new_size = elem_size * amount;
                 let align = mem::align_of::<T>();
@@ -653,7 +653,7 @@ impl<T, A: Alloc> RawVec<T, A> {
                 return Ok(());
             }
 
-            // Nothing we can really do about these checks :(
+            // Nothing we can really do about these checks, sadly.
             let new_cap = match strategy {
                 Exact => used_capacity.checked_add(needed_extra_capacity).ok_or(CapacityOverflow)?,
                 Amortized => self.amortized_new_size(used_capacity, needed_extra_capacity)?,
@@ -692,7 +692,7 @@ impl<T> RawVec<T, Global> {
     /// Converts the entire buffer into `Box<[T]>`.
     ///
     /// Note that this will correctly reconstitute any `cap` changes
-    /// that may have been performed. (see description of type for details)
+    /// that may have been performed. (See description of type for details.)
     ///
     /// # Undefined Behavior
     ///
@@ -700,7 +700,7 @@ impl<T> RawVec<T, Global> {
     /// the rules around uninitialized boxed values are not finalized yet,
     /// but until they are, it is advisable to avoid them.
     pub unsafe fn into_box(self) -> Box<[T]> {
-        // NOTE: not calling `capacity()` here, actually using the real `cap` field!
+        // NOTE: not calling `capacity()` here; actually using the real `cap` field!
         let slice = slice::from_raw_parts_mut(self.ptr(), self.cap);
         let output: Box<[T]> = Box::from_raw(slice);
         mem::forget(self);
@@ -709,7 +709,7 @@ impl<T> RawVec<T, Global> {
 }
 
 impl<T, A: Alloc> RawVec<T, A> {
-    /// Frees the memory owned by the RawVec *without* trying to Drop its contents.
+    /// Frees the memory owned by the `RawVec` *without* trying to drop its contents.
     pub unsafe fn dealloc_buffer(&mut self) {
         let elem_size = mem::size_of::<T>();
         if elem_size != 0 {
@@ -721,22 +721,20 @@ impl<T, A: Alloc> RawVec<T, A> {
 }
 
 unsafe impl<#[may_dangle] T, A: Alloc> Drop for RawVec<T, A> {
-    /// Frees the memory owned by the RawVec *without* trying to Drop its contents.
+    /// Frees the memory owned by the `RawVec` *without* trying to drop its contents.
     fn drop(&mut self) {
         unsafe { self.dealloc_buffer(); }
     }
 }
 
-
-
 // We need to guarantee the following:
-// * We don't ever allocate `> isize::MAX` byte-size objects
+// * We don't ever allocate `> isize::MAX` byte-size objects.
-// * We don't overflow `usize::MAX` and actually allocate too little
+// * We don't overflow `usize::MAX` and actually allocate too little.
 //
 // On 64-bit we just need to check for overflow since trying to allocate
 // `> isize::MAX` bytes will surely fail. On 32-bit and 16-bit we need to add
 // an extra guard for this in case we're running on a platform which can use
-// all 4GB in user-space. e.g., PAE or x32
+// all 4GB in user-space, e.g., PAE or x32.
 
 #[inline]
 fn alloc_guard(alloc_size: usize) -> Result<(), TryReserveError> {
@@ -751,5 +749,5 @@ fn alloc_guard(alloc_size: usize) -> Result<(), TryReserveError> {
 // ensure that the code generation related to these panics is minimal as there's
 // only one location which panics rather than a bunch throughout the module.
 fn capacity_overflow() -> ! {
-    panic!("capacity overflow")
+    panic!("capacity overflow");
 }

src/liballoc/raw_vec/tests.rs

@@ -5,12 +5,12 @@ fn allocator_param() {
     use crate::alloc::AllocErr;
 
     // Writing a test of integration between third-party
-    // allocators and RawVec is a little tricky because the RawVec
+    // allocators and `RawVec` is a little tricky because the `RawVec`
     // API does not expose fallible allocation methods, so we
     // cannot check what happens when allocator is exhausted
     // (beyond detecting a panic).
     //
-    // Instead, this just checks that the RawVec methods do at
+    // Instead, this just checks that the `RawVec` methods do at
     // least go through the Allocator API when it reserves
     // storage.
 
@@ -44,7 +44,7 @@ fn allocator_param() {
 fn reserve_does_not_overallocate() {
     {
         let mut v: RawVec<u32> = RawVec::new();
-        // First `reserve` allocates like `reserve_exact`
+        // First, `reserve` allocates like `reserve_exact`.
         v.reserve(0, 9);
         assert_eq!(9, v.capacity());
     }

src/liballoc/rc.rs

@@ -567,7 +567,7 @@ impl<T: ?Sized> Rc<T> {
     ///     let x = Rc::from_raw(x_ptr);
     ///     assert_eq!(&*x, "hello");
     ///
-    ///     // Further calls to `Rc::from_raw(x_ptr)` would be memory unsafe.
+    ///     // Further calls to `Rc::from_raw(x_ptr)` would be memory-unsafe.
     /// }
     ///
     /// // The memory was freed when `x` went out of scope above, so `x_ptr` is now dangling!

src/liballoc/sync.rs

@@ -547,7 +547,7 @@ impl<T: ?Sized> Arc<T> {
     ///     let x = Arc::from_raw(x_ptr);
     ///     assert_eq!(&*x, "hello");
     ///
-    ///     // Further calls to `Arc::from_raw(x_ptr)` would be memory unsafe.
+    ///     // Further calls to `Arc::from_raw(x_ptr)` would be memory-unsafe.
     /// }
     ///
     /// // The memory was freed when `x` went out of scope above, so `x_ptr` is now dangling!

src/libcore/any.rs

@@ -153,13 +153,13 @@ impl dyn Any {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn is<T: Any>(&self) -> bool {
-        // Get TypeId of the type this function is instantiated with
+        // Get `TypeId` of the type this function is instantiated with.
         let t = TypeId::of::<T>();
 
-        // Get TypeId of the type in the trait object
+        // Get `TypeId` of the type in the trait object.
         let concrete = self.type_id();
 
-        // Compare both TypeIds on equality
+        // Compare both `TypeId`s on equality.
         t == concrete
     }
 

src/libcore/marker.rs

@@ -602,10 +602,10 @@ unsafe impl<T: ?Sized> Freeze for *mut T {}
 unsafe impl<T: ?Sized> Freeze for &T {}
 unsafe impl<T: ?Sized> Freeze for &mut T {}
 
-/// Types which can be safely moved after being pinned.
+/// Types that can be safely moved after being pinned.
 ///
 /// Since Rust itself has no notion of immovable types, and considers moves
-/// (e.g. through assignment or [`mem::replace`]) to always be safe,
+/// (e.g., through assignment or [`mem::replace`]) to always be safe,
 /// this trait cannot prevent types from moving by itself.
 ///
 /// Instead it is used to prevent moves through the type system,

src/libcore/ptr/mod.rs

@@ -1042,7 +1042,7 @@ impl<T: ?Sized> *const T {
         (self as *const u8) == null()
     }
 
-    /// Cast to a pointer to a different type
+    /// Casts to a pointer of another type.
     #[stable(feature = "ptr_cast", since = "1.38.0")]
     #[inline]
     pub const fn cast<U>(self) -> *const U {
@@ -1726,7 +1726,7 @@ impl<T: ?Sized> *mut T {
         (self as *mut u8) == null_mut()
     }
 
-    /// Cast to a pointer to a different type
+    /// Casts to a pointer of another type.
     #[stable(feature = "ptr_cast", since = "1.38.0")]
     #[inline]
     pub const fn cast<U>(self) -> *mut U {

src/libcore/ptr/non_null.rs

@@ -125,7 +125,7 @@ impl<T: ?Sized> NonNull<T> {
         &mut *self.as_ptr()
     }
 
-    /// Cast to a pointer of another type
+    /// Casts to a pointer of another type.
     #[stable(feature = "nonnull_cast", since = "1.27.0")]
     #[inline]
     pub const fn cast<U>(self) -> NonNull<U> {

src/libstd/env.rs

@@ -290,7 +290,7 @@ impl Error for VarError {
 ///
 /// Note that while concurrent access to environment variables is safe in Rust,
 /// some platforms only expose inherently unsafe non-threadsafe APIs for
-/// inspecting the environment. As a result extra care needs to be taken when
+/// inspecting the environment. As a result, extra care needs to be taken when
 /// auditing calls to unsafe external FFI functions to ensure that any external
 /// environment accesses are properly synchronized with accesses in Rust.
 ///

src/libstd/error.rs

@@ -196,10 +196,10 @@ pub trait Error: Debug + Display {
     #[stable(feature = "error_source", since = "1.30.0")]
     fn source(&self) -> Option<&(dyn Error + 'static)> { None }
 
-    /// Gets the `TypeId` of `self`
+    /// Gets the `TypeId` of `self`.
     #[doc(hidden)]
     #[unstable(feature = "error_type_id",
-               reason = "this is memory unsafe to override in user code",
+               reason = "this is memory-unsafe to override in user code",
                issue = "60784")]
     fn type_id(&self, _: private::Internal) -> TypeId where Self: 'static {
         TypeId::of::<Self>()
@@ -601,19 +601,19 @@ impl Error for char::ParseCharError {
     }
 }
 
-// copied from any.rs
+// Copied from `any.rs`.
 impl dyn Error + 'static {
     /// Returns `true` if the boxed type is the same as `T`
     #[stable(feature = "error_downcast", since = "1.3.0")]
     #[inline]
     pub fn is<T: Error + 'static>(&self) -> bool {
-        // Get TypeId of the type this function is instantiated with
+        // Get `TypeId` of the type this function is instantiated with.
         let t = TypeId::of::<T>();
 
-        // Get TypeId of the type in the trait object
+        // Get `TypeId` of the type in the trait object.
         let boxed = self.type_id(private::Internal);
 
-        // Compare both TypeIds on equality
+        // Compare both `TypeId`s on equality.
         t == boxed
     }
 
@@ -647,21 +647,21 @@ impl dyn Error + 'static {
 }
 
 impl dyn Error + 'static + Send {
-    /// Forwards to the method defined on the type `Any`.
+    /// Forwards to the method defined on the type `dyn Error`.
     #[stable(feature = "error_downcast", since = "1.3.0")]
     #[inline]
     pub fn is<T: Error + 'static>(&self) -> bool {
         <dyn Error + 'static>::is::<T>(self)
     }
 
-    /// Forwards to the method defined on the type `Any`.
+    /// Forwards to the method defined on the type `dyn Error`.
     #[stable(feature = "error_downcast", since = "1.3.0")]
     #[inline]
     pub fn downcast_ref<T: Error + 'static>(&self) -> Option<&T> {
         <dyn Error + 'static>::downcast_ref::<T>(self)
     }
 
-    /// Forwards to the method defined on the type `Any`.
+    /// Forwards to the method defined on the type `dyn Error`.
     #[stable(feature = "error_downcast", since = "1.3.0")]
     #[inline]
     pub fn downcast_mut<T: Error + 'static>(&mut self) -> Option<&mut T> {
@@ -670,21 +670,21 @@ impl dyn Error + 'static + Send {
 }
 
 impl dyn Error + 'static + Send + Sync {
-    /// Forwards to the method defined on the type `Any`.
+    /// Forwards to the method defined on the type `dyn Error`.
     #[stable(feature = "error_downcast", since = "1.3.0")]
     #[inline]
     pub fn is<T: Error + 'static>(&self) -> bool {
         <dyn Error + 'static>::is::<T>(self)
     }
 
-    /// Forwards to the method defined on the type `Any`.
+    /// Forwards to the method defined on the type `dyn Error`.
     #[stable(feature = "error_downcast", since = "1.3.0")]
     #[inline]
     pub fn downcast_ref<T: Error + 'static>(&self) -> Option<&T> {
         <dyn Error + 'static>::downcast_ref::<T>(self)
     }
 
-    /// Forwards to the method defined on the type `Any`.
+    /// Forwards to the method defined on the type `dyn Error`.
     #[stable(feature = "error_downcast", since = "1.3.0")]
     #[inline]
     pub fn downcast_mut<T: Error + 'static>(&mut self) -> Option<&mut T> {
@@ -695,7 +695,7 @@ impl dyn Error + 'static + Send + Sync {
 impl dyn Error {
     #[inline]
     #[stable(feature = "error_downcast", since = "1.3.0")]
-    /// Attempt to downcast the box to a concrete type.
+    /// Attempts to downcast the box to a concrete type.
     pub fn downcast<T: Error + 'static>(self: Box<Self>) -> Result<Box<T>, Box<dyn Error>> {
         if self.is::<T>() {
             unsafe {
@@ -863,12 +863,12 @@ impl<'a> Iterator for ErrorIter<'a> {
 impl dyn Error + Send {
     #[inline]
     #[stable(feature = "error_downcast", since = "1.3.0")]
-    /// Attempt to downcast the box to a concrete type.
+    /// Attempts to downcast the box to a concrete type.
     pub fn downcast<T: Error + 'static>(self: Box<Self>)
                                         -> Result<Box<T>, Box<dyn Error + Send>> {
         let err: Box<dyn Error> = self;
         <dyn Error>::downcast(err).map_err(|s| unsafe {
-            // reapply the Send marker
+            // Reapply the `Send` marker.
             transmute::<Box<dyn Error>, Box<dyn Error + Send>>(s)
         })
     }
@@ -877,12 +877,12 @@ impl dyn Error + Send {
 impl dyn Error + Send + Sync {
     #[inline]
     #[stable(feature = "error_downcast", since = "1.3.0")]
-    /// Attempt to downcast the box to a concrete type.
+    /// Attempts to downcast the box to a concrete type.
     pub fn downcast<T: Error + 'static>(self: Box<Self>)
                                         -> Result<Box<T>, Box<Self>> {
         let err: Box<dyn Error> = self;
         <dyn Error>::downcast(err).map_err(|s| unsafe {
-            // reapply the Send+Sync marker
+            // Reapply the `Send + Sync` marker.
             transmute::<Box<dyn Error>, Box<dyn Error + Send + Sync>>(s)
         })
     }

src/libstd/ffi/c_str.rs

@@ -615,7 +615,7 @@ impl CString {
 }
 
 // Turns this `CString` into an empty string to prevent
-// memory unsafe code from working by accident. Inline
+// memory-unsafe code from working by accident. Inline
 // to prevent LLVM from optimizing it away in debug builds.
 #[stable(feature = "cstring_drop", since = "1.13.0")]
 impl Drop for CString {

src/libstd/process.rs

@@ -1595,7 +1595,7 @@ pub fn id() -> u32 {
 
 /// A trait for implementing arbitrary return types in the `main` function.
 ///
-/// The c-main function only supports to return integers as return type.
+/// The C-main function only supports to return integers as return type.
 /// So, every type implementing the `Termination` trait has to be converted
 /// to an integer.
 ///