rename MaybeUninit slice methods

RalfJung · RalfJung · commit dddc5ff8757f · 2020-09-02T08:53:29.000+02:00
first_ptr -&gt; slice_as_ptr
first_ptr_mut -&gt; slice_as_mut_ptr
slice_get_ref -&gt; slice_assume_init_ref
slice_get_mut -&gt; slice_assume_init_mut
diff --git a/library/alloc/src/collections/btree/node.rs b/library/alloc/src/collections/btree/node.rs
@@ -461,11 +461,15 @@ impl<'a, K, V, Type> NodeRef<marker::Mut<'a>, K, V, Type> {
 
 impl<'a, K: 'a, V: 'a, Type> NodeRef<marker::Immut<'a>, K, V, Type> {
     fn into_key_slice(self) -> &'a [K] {
-        unsafe { slice::from_raw_parts(MaybeUninit::first_ptr(&self.as_leaf().keys), self.len()) }
+        unsafe {
+            slice::from_raw_parts(MaybeUninit::slice_as_ptr(&self.as_leaf().keys), self.len())
+        }
     }
 
     fn into_val_slice(self) -> &'a [V] {
-        unsafe { slice::from_raw_parts(MaybeUninit::first_ptr(&self.as_leaf().vals), self.len()) }
+        unsafe {
+            slice::from_raw_parts(MaybeUninit::slice_as_ptr(&self.as_leaf().vals), self.len())
+        }
     }
 }
 
@@ -480,7 +484,7 @@ impl<'a, K: 'a, V: 'a, Type> NodeRef<marker::Mut<'a>, K, V, Type> {
         // SAFETY: The keys of a node must always be initialized up to length.
         unsafe {
             slice::from_raw_parts_mut(
-                MaybeUninit::first_ptr_mut(&mut (*self.as_leaf_mut()).keys),
+                MaybeUninit::slice_as_mut_ptr(&mut (*self.as_leaf_mut()).keys),
                 self.len(),
             )
         }
@@ -490,7 +494,7 @@ impl<'a, K: 'a, V: 'a, Type> NodeRef<marker::Mut<'a>, K, V, Type> {
         // SAFETY: The values of a node must always be initialized up to length.
         unsafe {
             slice::from_raw_parts_mut(
-                MaybeUninit::first_ptr_mut(&mut (*self.as_leaf_mut()).vals),
+                MaybeUninit::slice_as_mut_ptr(&mut (*self.as_leaf_mut()).vals),
                 self.len(),
             )
         }
@@ -506,10 +510,10 @@ impl<'a, K: 'a, V: 'a, Type> NodeRef<marker::Mut<'a>, K, V, Type> {
         let leaf = self.as_leaf_mut();
         // SAFETY: The keys and values of a node must always be initialized up to length.
         let keys = unsafe {
-            slice::from_raw_parts_mut(MaybeUninit::first_ptr_mut(&mut (*leaf).keys), len)
+            slice::from_raw_parts_mut(MaybeUninit::slice_as_mut_ptr(&mut (*leaf).keys), len)
         };
         let vals = unsafe {
-            slice::from_raw_parts_mut(MaybeUninit::first_ptr_mut(&mut (*leaf).vals), len)
+            slice::from_raw_parts_mut(MaybeUninit::slice_as_mut_ptr(&mut (*leaf).vals), len)
         };
         (keys, vals)
     }
@@ -588,7 +592,7 @@ impl<'a, K, V> NodeRef<marker::Mut<'a>, K, V, marker::Internal> {
             slice_insert(self.vals_mut(), 0, val);
             slice_insert(
                 slice::from_raw_parts_mut(
-                    MaybeUninit::first_ptr_mut(&mut self.as_internal_mut().edges),
+                    MaybeUninit::slice_as_mut_ptr(&mut self.as_internal_mut().edges),
                     self.len() + 1,
                 ),
                 0,
@@ -646,7 +650,7 @@ impl<'a, K, V> NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal> {
                 ForceResult::Internal(mut internal) => {
                     let edge = slice_remove(
                         slice::from_raw_parts_mut(
-                            MaybeUninit::first_ptr_mut(&mut internal.as_internal_mut().edges),
+                            MaybeUninit::slice_as_mut_ptr(&mut internal.as_internal_mut().edges),
                             old_len + 1,
                         ),
                         0,
@@ -933,7 +937,7 @@ impl<'a, K, V> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Internal>, marker::
 
             slice_insert(
                 slice::from_raw_parts_mut(
-                    MaybeUninit::first_ptr_mut(&mut self.node.as_internal_mut().edges),
+                    MaybeUninit::slice_as_mut_ptr(&mut self.node.as_internal_mut().edges),
                     self.node.len(),
                 ),
                 self.idx + 1,
diff --git a/library/core/src/array/iter.rs b/library/core/src/array/iter.rs
@@ -73,7 +73,7 @@ impl<T, const N: usize> IntoIter<T, N> {
         // SAFETY: We know that all elements within `alive` are properly initialized.
         unsafe {
             let slice = self.data.get_unchecked(self.alive.clone());
-            MaybeUninit::slice_get_ref(slice)
+            MaybeUninit::slice_assume_init_ref(slice)
         }
     }
 
@@ -82,7 +82,7 @@ impl<T, const N: usize> IntoIter<T, N> {
         // SAFETY: We know that all elements within `alive` are properly initialized.
         unsafe {
             let slice = self.data.get_unchecked_mut(self.alive.clone());
-            MaybeUninit::slice_get_mut(slice)
+            MaybeUninit::slice_assume_init_mut(slice)
         }
     }
 }
diff --git a/library/core/src/array/mod.rs b/library/core/src/array/mod.rs
@@ -410,7 +410,7 @@ impl<T, const N: usize> [T; N] {
         }
         let mut dst = MaybeUninit::uninit_array::<N>();
         let mut guard: Guard<U, N> =
-            Guard { dst: MaybeUninit::first_ptr_mut(&mut dst), initialized: 0 };
+            Guard { dst: MaybeUninit::slice_as_mut_ptr(&mut dst), initialized: 0 };
         for (src, dst) in IntoIter::new(self).zip(&mut dst) {
             dst.write(f(src));
             guard.initialized += 1;
diff --git a/library/core/src/fmt/num.rs b/library/core/src/fmt/num.rs
@@ -85,7 +85,10 @@ trait GenericRadix {
         // SAFETY: The only chars in `buf` are created by `Self::digit` which are assumed to be
         // valid UTF-8
         let buf = unsafe {
-            str::from_utf8_unchecked(slice::from_raw_parts(MaybeUninit::first_ptr(buf), buf.len()))
+            str::from_utf8_unchecked(slice::from_raw_parts(
+                MaybeUninit::slice_as_ptr(buf),
+                buf.len(),
+            ))
         };
         f.pad_integral(is_nonnegative, Self::PREFIX, buf)
     }
@@ -192,7 +195,7 @@ macro_rules! impl_Display {
             // 2^128 is about 3*10^38, so 39 gives an extra byte of space
             let mut buf = [MaybeUninit::<u8>::uninit(); 39];
             let mut curr = buf.len() as isize;
-            let buf_ptr = MaybeUninit::first_ptr_mut(&mut buf);
+            let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf);
             let lut_ptr = DEC_DIGITS_LUT.as_ptr();
 
             // SAFETY: Since `d1` and `d2` are always less than or equal to `198`, we
@@ -322,7 +325,7 @@ macro_rules! impl_Exp {
             // that `curr >= 0`.
             let mut buf = [MaybeUninit::<u8>::uninit(); 40];
             let mut curr = buf.len() as isize; //index for buf
-            let buf_ptr = MaybeUninit::first_ptr_mut(&mut buf);
+            let buf_ptr = MaybeUninit::slice_as_mut_ptr(&mut buf);
             let lut_ptr = DEC_DIGITS_LUT.as_ptr();
 
             // decode 2 chars at a time
@@ -370,7 +373,7 @@ macro_rules! impl_Exp {
 
             // stores 'e' (or 'E') and the up to 2-digit exponent
             let mut exp_buf = [MaybeUninit::<u8>::uninit(); 3];
-            let exp_ptr = MaybeUninit::first_ptr_mut(&mut exp_buf);
+            let exp_ptr = MaybeUninit::slice_as_mut_ptr(&mut exp_buf);
             // SAFETY: In either case, `exp_buf` is written within bounds and `exp_ptr[..len]`
             // is contained within `exp_buf` since `len <= 3`.
             let exp_slice = unsafe {
diff --git a/library/core/src/mem/maybe_uninit.rs b/library/core/src/mem/maybe_uninit.rs
@@ -281,7 +281,7 @@ impl<T> MaybeUninit<T> {
     /// # Examples
     ///
     /// ```no_run
-    /// #![feature(maybe_uninit_uninit_array, maybe_uninit_extra, maybe_uninit_slice_assume_init)]
+    /// #![feature(maybe_uninit_uninit_array, maybe_uninit_extra, maybe_uninit_slice)]
     ///
     /// use std::mem::MaybeUninit;
     ///
@@ -293,7 +293,7 @@ impl<T> MaybeUninit<T> {
     /// fn read(buf: &mut [MaybeUninit<u8>]) -> &[u8] {
     ///     unsafe {
     ///         let len = read_into_buffer(buf.as_mut_ptr() as *mut u8, buf.len());
-    ///         MaybeUninit::slice_get_ref(&buf[..len])
+    ///         MaybeUninit::slice_assume_init_ref(&buf[..len])
     ///     }
     /// }
     ///
@@ -303,6 +303,7 @@ impl<T> MaybeUninit<T> {
     #[unstable(feature = "maybe_uninit_uninit_array", issue = "none")]
     #[inline(always)]
     pub fn uninit_array<const LEN: usize>() -> [Self; LEN] {
+        // SAFETY: An uninitialized `[MaybeUninit<_>; LEN]` is valid.
         unsafe { MaybeUninit::<[MaybeUninit<T>; LEN]>::uninit().assume_init() }
     }
 
@@ -769,9 +770,13 @@ impl<T> MaybeUninit<T> {
     /// It is up to the caller to guarantee that the `MaybeUninit<T>` elements
     /// really are in an initialized state.
     /// Calling this when the content is not yet fully initialized causes undefined behavior.
-    #[unstable(feature = "maybe_uninit_slice_assume_init", issue = "none")]
+    ///
+    /// See [`assume_init_ref`] for more details and examples.
+    ///
+    /// [`assume_init_ref`]: MaybeUninit::assume_init_ref
+    #[unstable(feature = "maybe_uninit_slice", issue = "63569")]
     #[inline(always)]
-    pub unsafe fn slice_get_ref(slice: &[Self]) -> &[T] {
+    pub unsafe fn slice_assume_init_ref(slice: &[Self]) -> &[T] {
         // SAFETY: casting slice to a `*const [T]` is safe since the caller guarantees that
         // `slice` is initialized, and`MaybeUninit` is guaranteed to have the same layout as `T`.
         // The pointer obtained is valid since it refers to memory owned by `slice` which is a
@@ -786,9 +791,13 @@ impl<T> MaybeUninit<T> {
     /// It is up to the caller to guarantee that the `MaybeUninit<T>` elements
     /// really are in an initialized state.
     /// Calling this when the content is not yet fully initialized causes undefined behavior.
-    #[unstable(feature = "maybe_uninit_slice_assume_init", issue = "none")]
+    ///
+    /// See [`assume_init_mut`] for more details and examples.
+    ///
+    /// [`assume_init_mut`]: MaybeUninit::assume_init_mut
+    #[unstable(feature = "maybe_uninit_slice", issue = "63569")]
     #[inline(always)]
-    pub unsafe fn slice_get_mut(slice: &mut [Self]) -> &mut [T] {
+    pub unsafe fn slice_assume_init_mut(slice: &mut [Self]) -> &mut [T] {
         // SAFETY: similar to safety notes for `slice_get_ref`, but we have a
         // mutable reference which is also guaranteed to be valid for writes.
         unsafe { &mut *(slice as *mut [Self] as *mut [T]) }
@@ -797,14 +806,14 @@ impl<T> MaybeUninit<T> {
     /// Gets a pointer to the first element of the array.
     #[unstable(feature = "maybe_uninit_slice", issue = "63569")]
     #[inline(always)]
-    pub fn first_ptr(this: &[MaybeUninit<T>]) -> *const T {
+    pub fn slice_as_ptr(this: &[MaybeUninit<T>]) -> *const T {
         this as *const [MaybeUninit<T>] as *const T
     }
 
     /// Gets a mutable pointer to the first element of the array.
     #[unstable(feature = "maybe_uninit_slice", issue = "63569")]
     #[inline(always)]
-    pub fn first_ptr_mut(this: &mut [MaybeUninit<T>]) -> *mut T {
+    pub fn slice_as_mut_ptr(this: &mut [MaybeUninit<T>]) -> *mut T {
         this as *mut [MaybeUninit<T>] as *mut T
     }
 }
diff --git a/library/core/src/slice/sort.rs b/library/core/src/slice/sort.rs
@@ -299,8 +299,8 @@ where
 
         if start_l == end_l {
             // Trace `block_l` elements from the left side.
-            start_l = MaybeUninit::first_ptr_mut(&mut offsets_l);
-            end_l = MaybeUninit::first_ptr_mut(&mut offsets_l);
+            start_l = MaybeUninit::slice_as_mut_ptr(&mut offsets_l);
+            end_l = MaybeUninit::slice_as_mut_ptr(&mut offsets_l);
             let mut elem = l;
 
             for i in 0..block_l {
@@ -325,8 +325,8 @@ where
 
         if start_r == end_r {
             // Trace `block_r` elements from the right side.
-            start_r = MaybeUninit::first_ptr_mut(&mut offsets_r);
-            end_r = MaybeUninit::first_ptr_mut(&mut offsets_r);
+            start_r = MaybeUninit::slice_as_mut_ptr(&mut offsets_r);
+            end_r = MaybeUninit::slice_as_mut_ptr(&mut offsets_r);
             let mut elem = r;
 
             for i in 0..block_r {

Original file line number	Diff line number	Diff line change
`@@ -73,7 +73,7 @@ impl<T, const N: usize> IntoIter<T, N> {`
`73`	`73`	// SAFETY: We know that all elements within `alive` are properly initialized.
`74`	`74`	`unsafe {`
`75`	`75`	`let slice = self.data.get_unchecked(self.alive.clone());`
`76`		`- MaybeUninit::slice_get_ref(slice)`
	`76`	`+ MaybeUninit::slice_assume_init_ref(slice)`
`77`	`77`	`}`
`78`	`78`	`}`
`79`	`79`
`@@ -82,7 +82,7 @@ impl<T, const N: usize> IntoIter<T, N> {`
`82`	`82`	// SAFETY: We know that all elements within `alive` are properly initialized.
`83`	`83`	`unsafe {`
`84`	`84`	`let slice = self.data.get_unchecked_mut(self.alive.clone());`
`85`		`- MaybeUninit::slice_get_mut(slice)`
	`85`	`+ MaybeUninit::slice_assume_init_mut(slice)`
`86`	`86`	`}`
`87`	`87`	`}`
`88`	`88`	`}`
Original file line number	Diff line number	Diff line change
`@@ -410,7 +410,7 @@ impl<T, const N: usize> [T; N] {`
`410`	`410`	`}`
`411`	`411`	`let mut dst = MaybeUninit::uninit_array::<N>();`
`412`	`412`	`let mut guard: Guard<U, N> =`
`413`		`- Guard { dst: MaybeUninit::first_ptr_mut(&mut dst), initialized: 0 };`
	`413`	`+ Guard { dst: MaybeUninit::slice_as_mut_ptr(&mut dst), initialized: 0 };`
`414`	`414`	`for (src, dst) in IntoIter::new(self).zip(&mut dst) {`
`415`	`415`	`dst.write(f(src));`
`416`	`416`	`guard.initialized += 1;`