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

1 files changed, 74 insertions, 76 deletions

diff --git a/src/liballoc/raw_vec.rs b/src/liballoc/raw_vec.rs
index bc8a38f6b3a..f1c5904afe6 100644
--- a/src/liballoc/raw_vec.rs
+++ b/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-length allocations
-/// * 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 overflowing your length
-/// * Aborts on OOM or calls handle_alloc_error as applicable
-/// * Avoids freeing Unique::empty()
-/// * Contains a ptr::Unique and thus endows the user with all related benefits
+/// * Produces `Unique::empty()` on zero-sized types.
+/// * Produces `Unique::empty()` on zero-length allocations.
+/// * 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 overflowing your length.
+/// * Aborts on OOM or calls `handle_alloc_error` as applicable.
+/// * Avoids freeing `Unique::empty()`.
+/// * 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
-/// to handle the actual things *stored* inside of a 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`.
 ///
-/// 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
+/// 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
 /// that might occur with zero-sized types.
 ///
-/// However this means that you need to be careful when round-tripping this type
-/// with a `Box<[T]>`: `capacity()` won't yield the len. However `with_capacity`,
-/// `shrink_to_fit`, and `from_box` will actually set RawVec's private capacity
+/// The above means that you need to be careful when round-tripping this type with a
+/// `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
 /// 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
-    /// the returned RawVec.
+    /// Like `new`, but parameterized over the choice of allocator for
+    /// the returned `RawVec`.
     pub const fn new_in(a: A) -> Self {
-        // !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`
+        // `!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`:
         //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
-    /// allocator for the returned RawVec.
+    /// Like `with_capacity`, but parameterized over the choice of
+    /// 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
-    /// of allocator for the returned RawVec.
+    /// Like `with_capacity_zeroed`, but parameterized over the choice
+    /// 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)
-    /// 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 `usize::MAX`. Useful for implementing
+    /// Creates the biggest possible `RawVec` (on the system heap)
+    /// without allocating. If `T` has positive size, then this makes a
+    /// `RawVec` with capacity `0`. If `T` is zero-sized, then it makes a
+    /// `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
-    /// 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.
+    /// The `ptr` must be allocated (via the given allocator `a`), and with the given `capacity`.
+    /// 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.
     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
-    /// 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.
+    /// The `ptr` must be allocated (on the system heap), and with the given `capacity`.
+    /// 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.
     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
-            // 0, getting to here necessarily means the RawVec is overfull.
+            // Since we set the capacity to `usize::MAX` when `elem_size` is
+            // 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
-                    // would cause overflow
+                    // Skip to 4 because tiny `Vec`'s are dumb; but not if that
+                    // 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
-            // 0, getting to here necessarily means the RawVec is overfull.
+            // Since we set the capacity to `usize::MAX` when `elem_size` is
+            // 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 overflow `usize::MAX` and actually allocate too little
+// * We don't ever allocate `> isize::MAX` byte-size objects.
+// * 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");
 }