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
     ///