Rollup merge of #44072 - lukaramu:fix-doc-headings, r=steveklabnik

Fix inconsistent doc headings

This fixes headings reading "Unsafety" and "Example", they should be "Safety" and "Examples" according to RFC 1574.

r? @steveklabnik

src/liballoc/allocator.rs

@@ -110,7 +110,7 @@ impl Layout {
 
     /// Creates a layout, bypassing all checks.
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This function is unsafe as it does not verify that `align` is
     /// a power-of-two that is also less than or equal to 2^31, nor
@@ -485,7 +485,7 @@ pub unsafe trait Alloc {
     /// behavior, e.g. to ensure initialization to particular sets of
     /// bit patterns.)
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This function is unsafe because undefined behavior can result
     /// if the caller does not ensure that `layout` has non-zero size.
@@ -513,7 +513,7 @@ pub unsafe trait Alloc {
 
     /// Deallocate the memory referenced by `ptr`.
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This function is unsafe because undefined behavior can result
     /// if the caller does not ensure all of the following:
@@ -617,7 +617,7 @@ pub unsafe trait Alloc {
     /// behavior is well-defined (though underspecified) when this
     /// constraint is violated; further discussion below.
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This function is unsafe because undefined behavior can result
     /// if the caller does not ensure all of the following:
@@ -688,7 +688,7 @@ pub unsafe trait Alloc {
     /// Behaves like `alloc`, but also ensures that the contents
     /// are set to zero before being returned.
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This function is unsafe for the same reasons that `alloc` is.
     ///
@@ -714,7 +714,7 @@ pub unsafe trait Alloc {
     /// the returned block. For some `layout` inputs, like arrays, this
     /// may include extra storage usable for additional data.
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This function is unsafe for the same reasons that `alloc` is.
     ///
@@ -736,7 +736,7 @@ pub unsafe trait Alloc {
     /// the returned block. For some `layout` inputs, like arrays, this
     /// may include extra storage usable for additional data.
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This function is unsafe for the same reasons that `realloc` is.
     ///
@@ -770,7 +770,7 @@ pub unsafe trait Alloc {
     /// memory block referenced by `ptr` has not been transferred, and
     /// the contents of the memory block are unaltered.
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This function is unsafe because undefined behavior can result
     /// if the caller does not ensure all of the following:
@@ -827,7 +827,7 @@ pub unsafe trait Alloc {
     /// the memory block has not been transferred, and the contents of
     /// the memory block are unaltered.
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This function is unsafe because undefined behavior can result
     /// if the caller does not ensure all of the following:
@@ -920,7 +920,7 @@ pub unsafe trait Alloc {
     ///
     /// Captures a common usage pattern for allocators.
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This function is unsafe because undefined behavior can result
     /// if the caller does not ensure both:
@@ -993,7 +993,7 @@ pub unsafe trait Alloc {
     /// The returned block is suitable for passing to the
     /// `alloc`/`realloc` methods of this allocator.
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This function is unsafe because undefined behavior can result
     /// if the caller does not ensure all of the following:
@@ -1037,7 +1037,7 @@ pub unsafe trait Alloc {
     ///
     /// Captures a common usage pattern for allocators.
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This function is unsafe because undefined behavior can result
     /// if the caller does not ensure both:

src/liballoc/boxed.rs

@@ -633,7 +633,7 @@ impl<I: FusedIterator + ?Sized> FusedIterator for Box<I> {}
 /// that `FnBox` may be deprecated in the future if `Box<FnOnce()>`
 /// closures become directly usable.)
 ///
-/// ### Example
+/// # Examples
 ///
 /// Here is a snippet of code which creates a hashmap full of boxed
 /// once closures and then removes them one by one, calling each

src/liballoc/slice.rs

@@ -171,7 +171,7 @@ mod hack {
 impl<T> [T] {
     /// Returns the number of elements in the slice.
     ///
-    /// # Example
+    /// # Examples
     ///
     /// ```
     /// let a = [1, 2, 3];
@@ -185,7 +185,7 @@ impl<T> [T] {
 
     /// Returns `true` if the slice has a length of 0.
     ///
-    /// # Example
+    /// # Examples
     ///
     /// ```
     /// let a = [1, 2, 3];
@@ -523,7 +523,7 @@ impl<T> [T] {
 
     /// Reverses the order of elements in the slice, in place.
     ///
-    /// # Example
+    /// # Examples
     ///
     /// ```
     /// let mut v = [1, 2, 3];
@@ -580,7 +580,7 @@ impl<T> [T] {
     ///
     /// Panics if `size` is 0.
     ///
-    /// # Example
+    /// # Examples
     ///
     /// ```
     /// let slice = ['r', 'u', 's', 't'];
@@ -613,7 +613,7 @@ impl<T> [T] {
     ///
     /// Panics if `size` is 0.
     ///
-    /// # Example
+    /// # Examples
     ///
     /// ```
     /// let slice = ['l', 'o', 'r', 'e', 'm'];
@@ -1040,7 +1040,7 @@ impl<T> [T] {
     /// `Err` is returned, containing the index where a matching
     /// element could be inserted while maintaining sorted order.
     ///
-    /// # Example
+    /// # Examples
     ///
     /// Looks up a series of four elements. The first is found, with a
     /// uniquely determined position; the second and third are not
@@ -1074,7 +1074,7 @@ impl<T> [T] {
     /// `Err` is returned, containing the index where a matching
     /// element could be inserted while maintaining sorted order.
     ///
-    /// # Example
+    /// # Examples
     ///
     /// Looks up a series of four elements. The first is found, with a
     /// uniquely determined position; the second and third are not
@@ -1419,7 +1419,7 @@ impl<T> [T] {
     ///
     /// This function will panic if the two slices have different lengths.
     ///
-    /// # Example
+    /// # Examples
     ///
     /// ```
     /// let mut dst = [0, 0, 0];
@@ -1445,7 +1445,7 @@ impl<T> [T] {
     ///
     /// This function will panic if the two slices have different lengths.
     ///
-    /// # Example
+    /// # Examples
     ///
     /// ```
     /// let mut dst = [0, 0, 0];

src/liballoc/str.rs

@@ -1714,7 +1714,7 @@ impl str {
     ///
     /// [`Err`]: str/trait.FromStr.html#associatedtype.Err
     ///
-    /// # Example
+    /// # Examples
     ///
     /// Basic usage
     ///

src/libcore/cell.rs

@@ -998,7 +998,7 @@ impl<'b, T: ?Sized> Ref<'b, T> {
     /// A method would interfere with methods of the same name on the contents
     /// of a `RefCell` used through `Deref`.
     ///
-    /// # Example
+    /// # Examples
     ///
     /// ```
     /// use std::cell::{RefCell, Ref};
@@ -1040,7 +1040,7 @@ impl<'b, T: ?Sized> RefMut<'b, T> {
     /// `RefMut::map(...)`.  A method would interfere with methods of the same
     /// name on the contents of a `RefCell` used through `Deref`.
     ///
-    /// # Example
+    /// # Examples
     ///
     /// ```
     /// use std::cell::{RefCell, RefMut};

src/libcore/fmt/builders.rs

@@ -58,7 +58,7 @@ impl<'a, 'b: 'a> fmt::Write for PadAdapter<'a, 'b> {
 /// [`Formatter::debug_struct`](struct.Formatter.html#method.debug_struct)
 /// method.
 ///
-/// # Example
+/// # Examples
 ///
 /// ```
 /// use std::fmt;
@@ -153,7 +153,7 @@ impl<'a, 'b: 'a> DebugStruct<'a, 'b> {
 /// [`Formatter::debug_tuple`](struct.Formatter.html#method.debug_tuple)
 /// method.
 ///
-/// # Example
+/// # Examples
 ///
 /// ```
 /// use std::fmt;
@@ -290,7 +290,7 @@ impl<'a, 'b: 'a> DebugInner<'a, 'b> {
 /// [`Formatter::debug_set`](struct.Formatter.html#method.debug_set)
 /// method.
 ///
-/// # Example
+/// # Examples
 ///
 /// ```
 /// use std::fmt;
@@ -361,7 +361,7 @@ impl<'a, 'b: 'a> DebugSet<'a, 'b> {
 /// [`Formatter::debug_list`](struct.Formatter.html#method.debug_list)
 /// method.
 ///
-/// # Example
+/// # Examples
 ///
 /// ```
 /// use std::fmt;
@@ -432,7 +432,7 @@ impl<'a, 'b: 'a> DebugList<'a, 'b> {
 /// [`Formatter::debug_map`](struct.Formatter.html#method.debug_map)
 /// method.
 ///
-/// # Example
+/// # Examples
 ///
 /// ```
 /// use std::fmt;

src/libcore/mem.rs

@@ -901,7 +901,7 @@ impl<T> ManuallyDrop<T> {
 
     /// Manually drops the contained value.
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This function runs the destructor of the contained value and thus the wrapped value
     /// now represents uninitialized data. It is up to the user of this method to ensure the

src/libstd/io/mod.rs

@@ -522,7 +522,7 @@ pub trait Read {
     /// `Read`er - the method only takes `&self` so that it can be used through
     /// trait objects.
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This method is unsafe because a `Read`er could otherwise return a
     /// non-zeroing `Initializer` from another `Read` type without an `unsafe`
@@ -903,7 +903,7 @@ impl Initializer {
 
     /// Returns a new `Initializer` which will not zero out buffers.
     ///
-    /// # Unsafety
+    /// # Safety
     ///
     /// This may only be called by `Read`ers which guarantee that they will not
     /// read from buffers passed to `Read` methods, and that the return value of

src/libstd/memchr.rs

@@ -20,7 +20,7 @@
 /// magnitude faster than `haystack.iter().position(|&b| b == needle)`.
 /// (See benchmarks.)
 ///
-/// # Example
+/// # Examples
 ///
 /// This shows how to find the first position of a byte in a byte string.
 ///
@@ -40,7 +40,7 @@ pub fn memchr(needle: u8, haystack: &[u8]) -> Option<usize> {
 /// Returns the index corresponding to the last occurrence of `needle` in
 /// `haystack`, or `None` if one is not found.
 ///
-/// # Example
+/// # Examples
 ///
 /// This shows how to find the last position of a byte in a byte string.
 ///

src/libstd/sys/redox/ext/mod.rs

@@ -13,7 +13,7 @@
 //! For now, this module is limited to extracting file descriptors,
 //! but its functionality will grow over time.
 //!
-//! # Example
+//! # Examples
 //!
 //! ```no_run
 //! use std::fs::File;

src/libstd/sys/unix/ext/mod.rs

@@ -13,7 +13,7 @@
 //! For now, this module is limited to extracting file descriptors,
 //! but its functionality will grow over time.
 //!
-//! # Example
+//! # Examples
 //!
 //! ```no_run
 //! use std::fs::File;

src/libstd/thread/mod.rs

@@ -807,7 +807,7 @@ pub fn park_timeout_ms(ms: u32) {
 /// Platforms which do not support nanosecond precision for sleeping will have
 /// `dur` rounded up to the nearest granularity of time they can sleep for.
 ///
-/// # Example
+/// # Examples
 ///
 /// Waiting for the complete expiration of the timeout:
 ///