From 79449986b707c18df92622a53d83eddd6872d8ee Mon Sep 17 00:00:00 2001 From: Ivan Tham Date: Sun, 31 May 2020 17:16:47 +0800 Subject: [PATCH 1/2] Rearrange impl blocks with Deref as first The other blocks depends on Deref to make it easier for readers when reimplementing or reading the implementations. --- src/liballoc/vec.rs | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) diff --git a/src/liballoc/vec.rs b/src/liballoc/vec.rs index 42fb1f8c737..6409c66b081 100644 --- a/src/liballoc/vec.rs +++ b/src/liballoc/vec.rs @@ -1900,6 +1900,22 @@ unsafe impl IsZero for Option> { // Common trait implementations for Vec //////////////////////////////////////////////////////////////////////////////// +#[stable(feature = "rust1", since = "1.0.0")] +impl ops::Deref for Vec { + 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 ops::DerefMut for Vec { + 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 Clone for Vec { #[cfg(not(test))] @@ -1955,22 +1971,6 @@ impl> IndexMut for Vec { } } -#[stable(feature = "rust1", since = "1.0.0")] -impl ops::Deref for Vec { - 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 ops::DerefMut for Vec { - 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 FromIterator for Vec { #[inline] From 71404633e843e0e5a533c677a764c8cb7f2a55fb Mon Sep 17 00:00:00 2001 From: Ivan Tham Date: Sun, 31 May 2020 17:19:06 +0800 Subject: [PATCH 2/2] Merge raw_vec into_box with previous impl There are two separate `impl` which no special reason, it would be better to merge both of them. --- src/liballoc/raw_vec.rs | 50 ++++++++++++++++++++--------------------- 1 file changed, 24 insertions(+), 26 deletions(-) diff --git a/src/liballoc/raw_vec.rs b/src/liballoc/raw_vec.rs index 56e284a12fa..5b365f0387a 100644 --- a/src/liballoc/raw_vec.rs +++ b/src/liballoc/raw_vec.rs @@ -118,6 +118,30 @@ impl RawVec { RawVec::from_raw_parts(slice.as_mut_ptr(), slice.len()) } } + + /// Converts the entire buffer into `Box<[MaybeUninit]>` 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]> { + // 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, len); + Box::from_raw(slice) + } } impl RawVec { @@ -520,32 +544,6 @@ where Ok(memory) } -impl RawVec { - /// Converts the entire buffer into `Box<[MaybeUninit]>` 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]> { - // 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, len); - Box::from_raw(slice) - } -} - unsafe impl<#[may_dangle] T, A: AllocRef> Drop for RawVec { /// Frees the memory owned by the `RawVec` *without* trying to drop its contents. fn drop(&mut self) {