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author | Jules Bertholet <julesbertholet@quoi.xyz> | 2022-10-22 12:13:03 -0400 |
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committer | Jules Bertholet <julesbertholet@quoi.xyz> | 2023-04-26 23:41:07 -0400 |
commit | 075ee26b6884514a65b0822b8745a6f5f35e8720 (patch) | |
tree | 096ae71a14e1386ed1c9bdadcdd938d81812290a /library | |
parent | 1c42cb4ef0544fbfaa500216e53382d6b079c001 (diff) | |
download | rust-075ee26b6884514a65b0822b8745a6f5f35e8720.tar.gz |
Loosen `From<&[T]> for Box<[T]>` bound to T: Clone
Diffstat (limited to 'library')
-rw-r--r-- | library/alloc/src/boxed.rs | 38 |
1 files changed, 30 insertions, 8 deletions
diff --git a/library/alloc/src/boxed.rs b/library/alloc/src/boxed.rs index ad86c193098..2a26661cab4 100644 --- a/library/alloc/src/boxed.rs +++ b/library/alloc/src/boxed.rs @@ -1455,9 +1455,35 @@ where } } +/// Specialization trait used for `From<&[T]>`. +trait BoxFromSlice<T> { + fn from_slice(slice: &[T]) -> Self; +} + +#[cfg(not(no_global_oom_handling))] +impl<T: Clone> BoxFromSlice<T> for Box<[T]> { + #[inline] + default fn from_slice(slice: &[T]) -> Self { + slice.to_vec().into_boxed_slice() + } +} + +#[cfg(not(no_global_oom_handling))] +impl<T: Copy> BoxFromSlice<T> for Box<[T]> { + #[inline] + fn from_slice(slice: &[T]) -> Self { + let len = slice.len(); + let buf = RawVec::with_capacity(len); + unsafe { + ptr::copy_nonoverlapping(slice.as_ptr(), buf.ptr(), len); + buf.into_box(slice.len()).assume_init() + } + } +} + #[cfg(not(no_global_oom_handling))] #[stable(feature = "box_from_slice", since = "1.17.0")] -impl<T: Copy> From<&[T]> for Box<[T]> { +impl<T: Clone> From<&[T]> for Box<[T]> { /// Converts a `&[T]` into a `Box<[T]>` /// /// This conversion allocates on the heap @@ -1471,19 +1497,15 @@ impl<T: Copy> From<&[T]> for Box<[T]> { /// /// println!("{boxed_slice:?}"); /// ``` + #[inline] fn from(slice: &[T]) -> Box<[T]> { - let len = slice.len(); - let buf = RawVec::with_capacity(len); - unsafe { - ptr::copy_nonoverlapping(slice.as_ptr(), buf.ptr(), len); - buf.into_box(slice.len()).assume_init() - } + <Self as BoxFromSlice<T>>::from_slice(slice) } } #[cfg(not(no_global_oom_handling))] #[stable(feature = "box_from_cow", since = "1.45.0")] -impl<T: Copy> From<Cow<'_, [T]>> for Box<[T]> { +impl<T: Clone> From<Cow<'_, [T]>> for Box<[T]> { /// Converts a `Cow<'_, [T]>` into a `Box<[T]>` /// /// When `cow` is the `Cow::Borrowed` variant, this |