rust: alloc: remove our fork of the `alloc` crate

It is not used anymore as `VecExt` now provides the functionality we
depend on.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20240328013603.206764-5-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

1 files changed, 0 insertions, 115 deletions

diff --git a/rust/alloc/vec/extract_if.rs b/rust/alloc/vec/extract_if.rs
deleted file mode 100644
index f314a51d4d3d..000000000000
--- a/rust/alloc/vec/extract_if.rs
+++ /dev/null
@@ -1,115 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0 OR MIT
-
-use crate::alloc::{Allocator, Global};
-use core::ptr;
-use core::slice;
-
-use super::Vec;
-
-/// An iterator which uses a closure to determine if an element should be removed.
-///
-/// This struct is created by [`Vec::extract_if`].
-/// See its documentation for more.
-///
-/// # Example
-///
-/// ```
-/// #![feature(extract_if)]
-///
-/// let mut v = vec![0, 1, 2];
-/// let iter: std::vec::ExtractIf<'_, _, _> = v.extract_if(|x| *x % 2 == 0);
-/// ```
-#[unstable(feature = "extract_if", reason = "recently added", issue = "43244")]
-#[derive(Debug)]
-#[must_use = "iterators are lazy and do nothing unless consumed"]
-pub struct ExtractIf<
-    'a,
-    T,
-    F,
-    #[unstable(feature = "allocator_api", issue = "32838")] A: Allocator = Global,
-> where
-    F: FnMut(&mut T) -> bool,
-{
-    pub(super) vec: &'a mut Vec<T, A>,
-    /// The index of the item that will be inspected by the next call to `next`.
-    pub(super) idx: usize,
-    /// The number of items that have been drained (removed) thus far.
-    pub(super) del: usize,
-    /// The original length of `vec` prior to draining.
-    pub(super) old_len: usize,
-    /// The filter test predicate.
-    pub(super) pred: F,
-}
-
-impl<T, F, A: Allocator> ExtractIf<'_, T, F, A>
-where
-    F: FnMut(&mut T) -> bool,
-{
-    /// Returns a reference to the underlying allocator.
-    #[unstable(feature = "allocator_api", issue = "32838")]
-    #[inline]
-    pub fn allocator(&self) -> &A {
-        self.vec.allocator()
-    }
-}
-
-#[unstable(feature = "extract_if", reason = "recently added", issue = "43244")]
-impl<T, F, A: Allocator> Iterator for ExtractIf<'_, T, F, A>
-where
-    F: FnMut(&mut T) -> bool,
-{
-    type Item = T;
-
-    fn next(&mut self) -> Option<T> {
-        unsafe {
-            while self.idx < self.old_len {
-                let i = self.idx;
-                let v = slice::from_raw_parts_mut(self.vec.as_mut_ptr(), self.old_len);
-                let drained = (self.pred)(&mut v[i]);
-                // Update the index *after* the predicate is called. If the index
-                // is updated prior and the predicate panics, the element at this
-                // index would be leaked.
-                self.idx += 1;
-                if drained {
-                    self.del += 1;
-                    return Some(ptr::read(&v[i]));
-                } else if self.del > 0 {
-                    let del = self.del;
-                    let src: *const T = &v[i];
-                    let dst: *mut T = &mut v[i - del];
-                    ptr::copy_nonoverlapping(src, dst, 1);
-                }
-            }
-            None
-        }
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        (0, Some(self.old_len - self.idx))
-    }
-}
-
-#[unstable(feature = "extract_if", reason = "recently added", issue = "43244")]
-impl<T, F, A: Allocator> Drop for ExtractIf<'_, T, F, A>
-where
-    F: FnMut(&mut T) -> bool,
-{
-    fn drop(&mut self) {
-        unsafe {
-            if self.idx < self.old_len && self.del > 0 {
-                // This is a pretty messed up state, and there isn't really an
-                // obviously right thing to do. We don't want to keep trying
-                // to execute `pred`, so we just backshift all the unprocessed
-                // elements and tell the vec that they still exist. The backshift
-                // is required to prevent a double-drop of the last successfully
-                // drained item prior to a panic in the predicate.
-                let ptr = self.vec.as_mut_ptr();
-                let src = ptr.add(self.idx);
-                let dst = src.sub(self.del);
-                let tail_len = self.old_len - self.idx;
-                src.copy_to(dst, tail_len);
-            }
-            self.vec.set_len(self.old_len - self.del);
-        }
-    }
-}