Rollup merge of #72811 - pickfire:liballoc-impl, r=Amanieu

Liballoc impl

Mainly code rearrangements
This commit is contained in:
Ralf Jung 2020-06-08 09:55:28 +02:00 committed by GitHub
commit 13815e4b35
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2 changed files with 40 additions and 42 deletions

View File

@ -118,6 +118,30 @@ impl<T> RawVec<T, Global> {
RawVec::from_raw_parts(slice.as_mut_ptr(), slice.len())
}
}
/// Converts the entire buffer into `Box<[MaybeUninit<T>]>` with the specified `len`.
///
/// Note that this will correctly reconstitute any `cap` changes
/// that may have been performed. (See description of type for details.)
///
/// # Safety
///
/// * `len` must be greater than or equal to the most recently requested capacity, and
/// * `len` must be less than or equal to `self.capacity()`.
///
/// Note, that the requested capacity and `self.capacity()` could differ, as
/// an allocator could overallocate and return a greater memory block than requested.
pub unsafe fn into_box(self, len: usize) -> Box<[MaybeUninit<T>]> {
// Sanity-check one half of the safety requirement (we cannot check the other half).
debug_assert!(
len <= self.capacity(),
"`len` must be smaller than or equal to `self.capacity()`"
);
let me = ManuallyDrop::new(self);
let slice = slice::from_raw_parts_mut(me.ptr() as *mut MaybeUninit<T>, len);
Box::from_raw(slice)
}
}
impl<T, A: AllocRef> RawVec<T, A> {
@ -520,32 +544,6 @@ where
Ok(memory)
}
impl<T> RawVec<T, Global> {
/// Converts the entire buffer into `Box<[MaybeUninit<T>]>` with the specified `len`.
///
/// Note that this will correctly reconstitute any `cap` changes
/// that may have been performed. (See description of type for details.)
///
/// # Safety
///
/// * `len` must be greater than or equal to the most recently requested capacity, and
/// * `len` must be less than or equal to `self.capacity()`.
///
/// Note, that the requested capacity and `self.capacity()` could differ, as
/// an allocator could overallocate and return a greater memory block than requested.
pub unsafe fn into_box(self, len: usize) -> Box<[MaybeUninit<T>]> {
// Sanity-check one half of the safety requirement (we cannot check the other half).
debug_assert!(
len <= self.capacity(),
"`len` must be smaller than or equal to `self.capacity()`"
);
let me = ManuallyDrop::new(self);
let slice = slice::from_raw_parts_mut(me.ptr() as *mut MaybeUninit<T>, len);
Box::from_raw(slice)
}
}
unsafe impl<#[may_dangle] T, A: AllocRef> Drop for RawVec<T, A> {
/// Frees the memory owned by the `RawVec` *without* trying to drop its contents.
fn drop(&mut self) {

View File

@ -1905,6 +1905,22 @@ unsafe impl<T: ?Sized> IsZero for Option<Box<T>> {
// Common trait implementations for Vec
////////////////////////////////////////////////////////////////////////////////
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> ops::Deref for Vec<T> {
type Target = [T];
fn deref(&self) -> &[T] {
unsafe { slice::from_raw_parts(self.as_ptr(), self.len) }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> ops::DerefMut for Vec<T> {
fn deref_mut(&mut self) -> &mut [T] {
unsafe { slice::from_raw_parts_mut(self.as_mut_ptr(), self.len) }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: Clone> Clone for Vec<T> {
#[cfg(not(test))]
@ -1960,22 +1976,6 @@ impl<T, I: SliceIndex<[T]>> IndexMut<I> for Vec<T> {
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> ops::Deref for Vec<T> {
type Target = [T];
fn deref(&self) -> &[T] {
unsafe { slice::from_raw_parts(self.as_ptr(), self.len) }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> ops::DerefMut for Vec<T> {
fn deref_mut(&mut self) -> &mut [T] {
unsafe { slice::from_raw_parts_mut(self.as_mut_ptr(), self.len) }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> FromIterator<T> for Vec<T> {
#[inline]