Deleted vendor folder

1 files changed, 0 insertions, 755 deletions

diff --git a/vendor/rayon/src/slice/mergesort.rs b/vendor/rayon/src/slice/mergesort.rs
deleted file mode 100644
index fec309d..0000000
--- a/vendor/rayon/src/slice/mergesort.rs
+++ /dev/null
@@ -1,755 +0,0 @@
-//! Parallel merge sort.
-//!
-//! This implementation is copied verbatim from `std::slice::sort` and then parallelized.
-//! The only difference from the original is that the sequential `mergesort` returns
-//! `MergesortResult` and leaves descending arrays intact.
-
-use crate::iter::*;
-use crate::slice::ParallelSliceMut;
-use crate::SendPtr;
-use std::mem;
-use std::mem::size_of;
-use std::ptr;
-use std::slice;
-
-unsafe fn get_and_increment<T>(ptr: &mut *mut T) -> *mut T {
-    let old = *ptr;
-    *ptr = ptr.offset(1);
-    old
-}
-
-unsafe fn decrement_and_get<T>(ptr: &mut *mut T) -> *mut T {
-    *ptr = ptr.offset(-1);
-    *ptr
-}
-
-/// When dropped, copies from `src` into `dest` a sequence of length `len`.
-struct CopyOnDrop<T> {
-    src: *const T,
-    dest: *mut T,
-    len: usize,
-}
-
-impl<T> Drop for CopyOnDrop<T> {
-    fn drop(&mut self) {
-        unsafe {
-            ptr::copy_nonoverlapping(self.src, self.dest, self.len);
-        }
-    }
-}
-
-/// Inserts `v[0]` into pre-sorted sequence `v[1..]` so that whole `v[..]` becomes sorted.
-///
-/// This is the integral subroutine of insertion sort.
-fn insert_head<T, F>(v: &mut [T], is_less: &F)
-where
-    F: Fn(&T, &T) -> bool,
-{
-    if v.len() >= 2 && is_less(&v[1], &v[0]) {
-        unsafe {
-            // There are three ways to implement insertion here:
-            //
-            // 1. Swap adjacent elements until the first one gets to its final destination.
-            //    However, this way we copy data around more than is necessary. If elements are big
-            //    structures (costly to copy), this method will be slow.
-            //
-            // 2. Iterate until the right place for the first element is found. Then shift the
-            //    elements succeeding it to make room for it and finally place it into the
-            //    remaining hole. This is a good method.
-            //
-            // 3. Copy the first element into a temporary variable. Iterate until the right place
-            //    for it is found. As we go along, copy every traversed element into the slot
-            //    preceding it. Finally, copy data from the temporary variable into the remaining
-            //    hole. This method is very good. Benchmarks demonstrated slightly better
-            //    performance than with the 2nd method.
-            //
-            // All methods were benchmarked, and the 3rd showed best results. So we chose that one.
-            let tmp = mem::ManuallyDrop::new(ptr::read(&v[0]));
-
-            // Intermediate state of the insertion process is always tracked by `hole`, which
-            // serves two purposes:
-            // 1. Protects integrity of `v` from panics in `is_less`.
-            // 2. Fills the remaining hole in `v` in the end.
-            //
-            // Panic safety:
-            //
-            // If `is_less` panics at any point during the process, `hole` will get dropped and
-            // fill the hole in `v` with `tmp`, thus ensuring that `v` still holds every object it
-            // initially held exactly once.
-            let mut hole = InsertionHole {
-                src: &*tmp,
-                dest: &mut v[1],
-            };
-            ptr::copy_nonoverlapping(&v[1], &mut v[0], 1);
-
-            for i in 2..v.len() {
-                if !is_less(&v[i], &*tmp) {
-                    break;
-                }
-                ptr::copy_nonoverlapping(&v[i], &mut v[i - 1], 1);
-                hole.dest = &mut v[i];
-            }
-            // `hole` gets dropped and thus copies `tmp` into the remaining hole in `v`.
-        }
-    }
-
-    // When dropped, copies from `src` into `dest`.
-    struct InsertionHole<T> {
-        src: *const T,
-        dest: *mut T,
-    }
-
-    impl<T> Drop for InsertionHole<T> {
-        fn drop(&mut self) {
-            unsafe {
-                ptr::copy_nonoverlapping(self.src, self.dest, 1);
-            }
-        }
-    }
-}
-
-/// Merges non-decreasing runs `v[..mid]` and `v[mid..]` using `buf` as temporary storage, and
-/// stores the result into `v[..]`.
-///
-/// # Safety
-///
-/// The two slices must be non-empty and `mid` must be in bounds. Buffer `buf` must be long enough
-/// to hold a copy of the shorter slice. Also, `T` must not be a zero-sized type.
-unsafe fn merge<T, F>(v: &mut [T], mid: usize, buf: *mut T, is_less: &F)
-where
-    F: Fn(&T, &T) -> bool,
-{
-    let len = v.len();
-    let v = v.as_mut_ptr();
-    let v_mid = v.add(mid);
-    let v_end = v.add(len);
-
-    // The merge process first copies the shorter run into `buf`. Then it traces the newly copied
-    // run and the longer run forwards (or backwards), comparing their next unconsumed elements and
-    // copying the lesser (or greater) one into `v`.
-    //
-    // As soon as the shorter run is fully consumed, the process is done. If the longer run gets
-    // consumed first, then we must copy whatever is left of the shorter run into the remaining
-    // hole in `v`.
-    //
-    // Intermediate state of the process is always tracked by `hole`, which serves two purposes:
-    // 1. Protects integrity of `v` from panics in `is_less`.
-    // 2. Fills the remaining hole in `v` if the longer run gets consumed first.
-    //
-    // Panic safety:
-    //
-    // If `is_less` panics at any point during the process, `hole` will get dropped and fill the
-    // hole in `v` with the unconsumed range in `buf`, thus ensuring that `v` still holds every
-    // object it initially held exactly once.
-    let mut hole;
-
-    if mid <= len - mid {
-        // The left run is shorter.
-        ptr::copy_nonoverlapping(v, buf, mid);
-        hole = MergeHole {
-            start: buf,
-            end: buf.add(mid),
-            dest: v,
-        };
-
-        // Initially, these pointers point to the beginnings of their arrays.
-        let left = &mut hole.start;
-        let mut right = v_mid;
-        let out = &mut hole.dest;
-
-        while *left < hole.end && right < v_end {
-            // Consume the lesser side.
-            // If equal, prefer the left run to maintain stability.
-            let to_copy = if is_less(&*right, &**left) {
-                get_and_increment(&mut right)
-            } else {
-                get_and_increment(left)
-            };
-            ptr::copy_nonoverlapping(to_copy, get_and_increment(out), 1);
-        }
-    } else {
-        // The right run is shorter.
-        ptr::copy_nonoverlapping(v_mid, buf, len - mid);
-        hole = MergeHole {
-            start: buf,
-            end: buf.add(len - mid),
-            dest: v_mid,
-        };
-
-        // Initially, these pointers point past the ends of their arrays.
-        let left = &mut hole.dest;
-        let right = &mut hole.end;
-        let mut out = v_end;
-
-        while v < *left && buf < *right {
-            // Consume the greater side.
-            // If equal, prefer the right run to maintain stability.
-            let to_copy = if is_less(&*right.offset(-1), &*left.offset(-1)) {
-                decrement_and_get(left)
-            } else {
-                decrement_and_get(right)
-            };
-            ptr::copy_nonoverlapping(to_copy, decrement_and_get(&mut out), 1);
-        }
-    }
-    // Finally, `hole` gets dropped. If the shorter run was not fully consumed, whatever remains of
-    // it will now be copied into the hole in `v`.
-
-    // When dropped, copies the range `start..end` into `dest..`.
-    struct MergeHole<T> {
-        start: *mut T,
-        end: *mut T,
-        dest: *mut T,
-    }
-
-    impl<T> Drop for MergeHole<T> {
-        fn drop(&mut self) {
-            // `T` is not a zero-sized type, so it's okay to divide by its size.
-            unsafe {
-                let len = self.end.offset_from(self.start) as usize;
-                ptr::copy_nonoverlapping(self.start, self.dest, len);
-            }
-        }
-    }
-}
-
-/// The result of merge sort.
-#[must_use]
-#[derive(Clone, Copy, PartialEq, Eq)]
-enum MergesortResult {
-    /// The slice has already been sorted.
-    NonDescending,
-    /// The slice has been descending and therefore it was left intact.
-    Descending,
-    /// The slice was sorted.
-    Sorted,
-}
-
-/// A sorted run that starts at index `start` and is of length `len`.
-#[derive(Clone, Copy)]
-struct Run {
-    start: usize,
-    len: usize,
-}
-
-/// Examines the stack of runs and identifies the next pair of runs to merge. More specifically,
-/// if `Some(r)` is returned, that means `runs[r]` and `runs[r + 1]` must be merged next. If the
-/// algorithm should continue building a new run instead, `None` is returned.
-///
-/// TimSort is infamous for its buggy implementations, as described here:
-/// http://envisage-project.eu/timsort-specification-and-verification/
-///
-/// The gist of the story is: we must enforce the invariants on the top four runs on the stack.
-/// Enforcing them on just top three is not sufficient to ensure that the invariants will still
-/// hold for *all* runs in the stack.
-///
-/// This function correctly checks invariants for the top four runs. Additionally, if the top
-/// run starts at index 0, it will always demand a merge operation until the stack is fully
-/// collapsed, in order to complete the sort.
-#[inline]
-fn collapse(runs: &[Run]) -> Option<usize> {
-    let n = runs.len();
-
-    if n >= 2
-        && (runs[n - 1].start == 0
-            || runs[n - 2].len <= runs[n - 1].len
-            || (n >= 3 && runs[n - 3].len <= runs[n - 2].len + runs[n - 1].len)
-            || (n >= 4 && runs[n - 4].len <= runs[n - 3].len + runs[n - 2].len))
-    {
-        if n >= 3 && runs[n - 3].len < runs[n - 1].len {
-            Some(n - 3)
-        } else {
-            Some(n - 2)
-        }
-    } else {
-        None
-    }
-}
-
-/// Sorts a slice using merge sort, unless it is already in descending order.
-///
-/// This function doesn't modify the slice if it is already non-descending or descending.
-/// Otherwise, it sorts the slice into non-descending order.
-///
-/// This merge sort borrows some (but not all) ideas from TimSort, which is described in detail
-/// [here](https://github.com/python/cpython/blob/main/Objects/listsort.txt).
-///
-/// The algorithm identifies strictly descending and non-descending subsequences, which are called
-/// natural runs. There is a stack of pending runs yet to be merged. Each newly found run is pushed
-/// onto the stack, and then some pairs of adjacent runs are merged until these two invariants are
-/// satisfied:
-///
-/// 1. for every `i` in `1..runs.len()`: `runs[i - 1].len > runs[i].len`
-/// 2. for every `i` in `2..runs.len()`: `runs[i - 2].len > runs[i - 1].len + runs[i].len`
-///
-/// The invariants ensure that the total running time is *O*(*n* \* log(*n*)) worst-case.
-///
-/// # Safety
-///
-/// The argument `buf` is used as a temporary buffer and must be at least as long as `v`.
-unsafe fn mergesort<T, F>(v: &mut [T], buf: *mut T, is_less: &F) -> MergesortResult
-where
-    T: Send,
-    F: Fn(&T, &T) -> bool + Sync,
-{
-    // Very short runs are extended using insertion sort to span at least this many elements.
-    const MIN_RUN: usize = 10;
-
-    let len = v.len();
-
-    // In order to identify natural runs in `v`, we traverse it backwards. That might seem like a
-    // strange decision, but consider the fact that merges more often go in the opposite direction
-    // (forwards). According to benchmarks, merging forwards is slightly faster than merging
-    // backwards. To conclude, identifying runs by traversing backwards improves performance.
-    let mut runs = vec![];
-    let mut end = len;
-    while end > 0 {
-        // Find the next natural run, and reverse it if it's strictly descending.
-        let mut start = end - 1;
-
-        if start > 0 {
-            start -= 1;
-
-            if is_less(v.get_unchecked(start + 1), v.get_unchecked(start)) {
-                while start > 0 && is_less(v.get_unchecked(start), v.get_unchecked(start - 1)) {
-                    start -= 1;
-                }
-
-                // If this descending run covers the whole slice, return immediately.
-                if start == 0 && end == len {
-                    return MergesortResult::Descending;
-                } else {
-                    v[start..end].reverse();
-                }
-            } else {
-                while start > 0 && !is_less(v.get_unchecked(start), v.get_unchecked(start - 1)) {
-                    start -= 1;
-                }
-
-                // If this non-descending run covers the whole slice, return immediately.
-                if end - start == len {
-                    return MergesortResult::NonDescending;
-                }
-            }
-        }
-
-        // Insert some more elements into the run if it's too short. Insertion sort is faster than
-        // merge sort on short sequences, so this significantly improves performance.
-        while start > 0 && end - start < MIN_RUN {
-            start -= 1;
-            insert_head(&mut v[start..end], &is_less);
-        }
-
-        // Push this run onto the stack.
-        runs.push(Run {
-            start,
-            len: end - start,
-        });
-        end = start;
-
-        // Merge some pairs of adjacent runs to satisfy the invariants.
-        while let Some(r) = collapse(&runs) {
-            let left = runs[r + 1];
-            let right = runs[r];
-            merge(
-                &mut v[left.start..right.start + right.len],
-                left.len,
-                buf,
-                &is_less,
-            );
-
-            runs[r] = Run {
-                start: left.start,
-                len: left.len + right.len,
-            };
-            runs.remove(r + 1);
-        }
-    }
-
-    // Finally, exactly one run must remain in the stack.
-    debug_assert!(runs.len() == 1 && runs[0].start == 0 && runs[0].len == len);
-
-    // The original order of the slice was neither non-descending nor descending.
-    MergesortResult::Sorted
-}
-
-////////////////////////////////////////////////////////////////////////////
-// Everything above this line is copied from `std::slice::sort` (with very minor tweaks).
-// Everything below this line is parallelization.
-////////////////////////////////////////////////////////////////////////////
-
-/// Splits two sorted slices so that they can be merged in parallel.
-///
-/// Returns two indices `(a, b)` so that slices `left[..a]` and `right[..b]` come before
-/// `left[a..]` and `right[b..]`.
-fn split_for_merge<T, F>(left: &[T], right: &[T], is_less: &F) -> (usize, usize)
-where
-    F: Fn(&T, &T) -> bool,
-{
-    let left_len = left.len();
-    let right_len = right.len();
-
-    if left_len >= right_len {
-        let left_mid = left_len / 2;
-
-        // Find the first element in `right` that is greater than or equal to `left[left_mid]`.
-        let mut a = 0;
-        let mut b = right_len;
-        while a < b {
-            let m = a + (b - a) / 2;
-            if is_less(&right[m], &left[left_mid]) {
-                a = m + 1;
-            } else {
-                b = m;
-            }
-        }
-
-        (left_mid, a)
-    } else {
-        let right_mid = right_len / 2;
-
-        // Find the first element in `left` that is greater than `right[right_mid]`.
-        let mut a = 0;
-        let mut b = left_len;
-        while a < b {
-            let m = a + (b - a) / 2;
-            if is_less(&right[right_mid], &left[m]) {
-                b = m;
-            } else {
-                a = m + 1;
-            }
-        }
-
-        (a, right_mid)
-    }
-}
-
-/// Merges slices `left` and `right` in parallel and stores the result into `dest`.
-///
-/// # Safety
-///
-/// The `dest` pointer must have enough space to store the result.
-///
-/// Even if `is_less` panics at any point during the merge process, this function will fully copy
-/// all elements from `left` and `right` into `dest` (not necessarily in sorted order).
-unsafe fn par_merge<T, F>(left: &mut [T], right: &mut [T], dest: *mut T, is_less: &F)
-where
-    T: Send,
-    F: Fn(&T, &T) -> bool + Sync,
-{
-    // Slices whose lengths sum up to this value are merged sequentially. This number is slightly
-    // larger than `CHUNK_LENGTH`, and the reason is that merging is faster than merge sorting, so
-    // merging needs a bit coarser granularity in order to hide the overhead of Rayon's task
-    // scheduling.
-    const MAX_SEQUENTIAL: usize = 5000;
-
-    let left_len = left.len();
-    let right_len = right.len();
-
-    // Intermediate state of the merge process, which serves two purposes:
-    // 1. Protects integrity of `dest` from panics in `is_less`.
-    // 2. Copies the remaining elements as soon as one of the two sides is exhausted.
-    //
-    // Panic safety:
-    //
-    // If `is_less` panics at any point during the merge process, `s` will get dropped and copy the
-    // remaining parts of `left` and `right` into `dest`.
-    let mut s = State {
-        left_start: left.as_mut_ptr(),
-        left_end: left.as_mut_ptr().add(left_len),
-        right_start: right.as_mut_ptr(),
-        right_end: right.as_mut_ptr().add(right_len),
-        dest,
-    };
-
-    if left_len == 0 || right_len == 0 || left_len + right_len < MAX_SEQUENTIAL {
-        while s.left_start < s.left_end && s.right_start < s.right_end {
-            // Consume the lesser side.
-            // If equal, prefer the left run to maintain stability.
-            let to_copy = if is_less(&*s.right_start, &*s.left_start) {
-                get_and_increment(&mut s.right_start)
-            } else {
-                get_and_increment(&mut s.left_start)
-            };
-            ptr::copy_nonoverlapping(to_copy, get_and_increment(&mut s.dest), 1);
-        }
-    } else {
-        // Function `split_for_merge` might panic. If that happens, `s` will get destructed and copy
-        // the whole `left` and `right` into `dest`.
-        let (left_mid, right_mid) = split_for_merge(left, right, is_less);
-        let (left_l, left_r) = left.split_at_mut(left_mid);
-        let (right_l, right_r) = right.split_at_mut(right_mid);
-
-        // Prevent the destructor of `s` from running. Rayon will ensure that both calls to
-        // `par_merge` happen. If one of the two calls panics, they will ensure that elements still
-        // get copied into `dest_left` and `dest_right``.
-        mem::forget(s);
-
-        // Wrap pointers in SendPtr so that they can be sent to another thread
-        // See the documentation of SendPtr for a full explanation
-        let dest_l = SendPtr(dest);
-        let dest_r = SendPtr(dest.add(left_l.len() + right_l.len()));
-        rayon_core::join(
-            move || par_merge(left_l, right_l, dest_l.get(), is_less),
-            move || par_merge(left_r, right_r, dest_r.get(), is_less),
-        );
-    }
-    // Finally, `s` gets dropped if we used sequential merge, thus copying the remaining elements
-    // all at once.
-
-    // When dropped, copies arrays `left_start..left_end` and `right_start..right_end` into `dest`,
-    // in that order.
-    struct State<T> {
-        left_start: *mut T,
-        left_end: *mut T,
-        right_start: *mut T,
-        right_end: *mut T,
-        dest: *mut T,
-    }
-
-    impl<T> Drop for State<T> {
-        fn drop(&mut self) {
-            let size = size_of::<T>();
-            let left_len = (self.left_end as usize - self.left_start as usize) / size;
-            let right_len = (self.right_end as usize - self.right_start as usize) / size;
-
-            // Copy array `left`, followed by `right`.
-            unsafe {
-                ptr::copy_nonoverlapping(self.left_start, self.dest, left_len);
-                self.dest = self.dest.add(left_len);
-                ptr::copy_nonoverlapping(self.right_start, self.dest, right_len);
-            }
-        }
-    }
-}
-
-/// Recursively merges pre-sorted chunks inside `v`.
-///
-/// Chunks of `v` are stored in `chunks` as intervals (inclusive left and exclusive right bound).
-/// Argument `buf` is an auxiliary buffer that will be used during the procedure.
-/// If `into_buf` is true, the result will be stored into `buf`, otherwise it will be in `v`.
-///
-/// # Safety
-///
-/// The number of chunks must be positive and they must be adjacent: the right bound of each chunk
-/// must equal the left bound of the following chunk.
-///
-/// The buffer must be at least as long as `v`.
-unsafe fn recurse<T, F>(
-    v: *mut T,
-    buf: *mut T,
-    chunks: &[(usize, usize)],
-    into_buf: bool,
-    is_less: &F,
-) where
-    T: Send,
-    F: Fn(&T, &T) -> bool + Sync,
-{
-    let len = chunks.len();
-    debug_assert!(len > 0);
-
-    // Base case of the algorithm.
-    // If only one chunk is remaining, there's no more work to split and merge.
-    if len == 1 {
-        if into_buf {
-            // Copy the chunk from `v` into `buf`.
-            let (start, end) = chunks[0];
-            let src = v.add(start);
-            let dest = buf.add(start);
-            ptr::copy_nonoverlapping(src, dest, end - start);
-        }
-        return;
-    }
-
-    // Split the chunks into two halves.
-    let (start, _) = chunks[0];
-    let (mid, _) = chunks[len / 2];
-    let (_, end) = chunks[len - 1];
-    let (left, right) = chunks.split_at(len / 2);
-
-    // After recursive calls finish we'll have to merge chunks `(start, mid)` and `(mid, end)` from
-    // `src` into `dest`. If the current invocation has to store the result into `buf`, we'll
-    // merge chunks from `v` into `buf`, and vice versa.
-    //
-    // Recursive calls flip `into_buf` at each level of recursion. More concretely, `par_merge`
-    // merges chunks from `buf` into `v` at the first level, from `v` into `buf` at the second
-    // level etc.
-    let (src, dest) = if into_buf { (v, buf) } else { (buf, v) };
-
-    // Panic safety:
-    //
-    // If `is_less` panics at any point during the recursive calls, the destructor of `guard` will
-    // be executed, thus copying everything from `src` into `dest`. This way we ensure that all
-    // chunks are in fact copied into `dest`, even if the merge process doesn't finish.
-    let guard = CopyOnDrop {
-        src: src.add(start),
-        dest: dest.add(start),
-        len: end - start,
-    };
-
-    // Wrap pointers in SendPtr so that they can be sent to another thread
-    // See the documentation of SendPtr for a full explanation
-    let v = SendPtr(v);
-    let buf = SendPtr(buf);
-    rayon_core::join(
-        move || recurse(v.get(), buf.get(), left, !into_buf, is_less),
-        move || recurse(v.get(), buf.get(), right, !into_buf, is_less),
-    );
-
-    // Everything went all right - recursive calls didn't panic.
-    // Forget the guard in order to prevent its destructor from running.
-    mem::forget(guard);
-
-    // Merge chunks `(start, mid)` and `(mid, end)` from `src` into `dest`.
-    let src_left = slice::from_raw_parts_mut(src.add(start), mid - start);
-    let src_right = slice::from_raw_parts_mut(src.add(mid), end - mid);
-    par_merge(src_left, src_right, dest.add(start), is_less);
-}
-
-/// Sorts `v` using merge sort in parallel.
-///
-/// The algorithm is stable, allocates memory, and `O(n log n)` worst-case.
-/// The allocated temporary buffer is of the same length as is `v`.
-pub(super) fn par_mergesort<T, F>(v: &mut [T], is_less: F)
-where
-    T: Send,
-    F: Fn(&T, &T) -> bool + Sync,
-{
-    // Slices of up to this length get sorted using insertion sort in order to avoid the cost of
-    // buffer allocation.
-    const MAX_INSERTION: usize = 20;
-    // The length of initial chunks. This number is as small as possible but so that the overhead
-    // of Rayon's task scheduling is still negligible.
-    const CHUNK_LENGTH: usize = 2000;
-
-    // Sorting has no meaningful behavior on zero-sized types.
-    if size_of::<T>() == 0 {
-        return;
-    }
-
-    let len = v.len();
-
-    // Short slices get sorted in-place via insertion sort to avoid allocations.
-    if len <= MAX_INSERTION {
-        if len >= 2 {
-            for i in (0..len - 1).rev() {
-                insert_head(&mut v[i..], &is_less);
-            }
-        }
-        return;
-    }
-
-    // Allocate a buffer to use as scratch memory. We keep the length 0 so we can keep in it
-    // shallow copies of the contents of `v` without risking the dtors running on copies if
-    // `is_less` panics.
-    let mut buf = Vec::<T>::with_capacity(len);
-    let buf = buf.as_mut_ptr();
-
-    // If the slice is not longer than one chunk would be, do sequential merge sort and return.
-    if len <= CHUNK_LENGTH {
-        let res = unsafe { mergesort(v, buf, &is_less) };
-        if res == MergesortResult::Descending {
-            v.reverse();
-        }
-        return;
-    }
-
-    // Split the slice into chunks and merge sort them in parallel.
-    // However, descending chunks will not be sorted - they will be simply left intact.
-    let mut iter = {
-        // Wrap pointer in SendPtr so that it can be sent to another thread
-        // See the documentation of SendPtr for a full explanation
-        let buf = SendPtr(buf);
-        let is_less = &is_less;
-
-        v.par_chunks_mut(CHUNK_LENGTH)
-            .with_max_len(1)
-            .enumerate()
-            .map(move |(i, chunk)| {
-                let l = CHUNK_LENGTH * i;
-                let r = l + chunk.len();
-                unsafe {
-                    let buf = buf.get().add(l);
-                    (l, r, mergesort(chunk, buf, is_less))
-                }
-            })
-            .collect::<Vec<_>>()
-            .into_iter()
-            .peekable()
-    };
-
-    // Now attempt to concatenate adjacent chunks that were left intact.
-    let mut chunks = Vec::with_capacity(iter.len());
-
-    while let Some((a, mut b, res)) = iter.next() {
-        // If this chunk was not modified by the sort procedure...
-        if res != MergesortResult::Sorted {
-            while let Some(&(x, y, r)) = iter.peek() {
-                // If the following chunk is of the same type and can be concatenated...
-                if r == res && (r == MergesortResult::Descending) == is_less(&v[x], &v[x - 1]) {
-                    // Concatenate them.
-                    b = y;
-                    iter.next();
-                } else {
-                    break;
-                }
-            }
-        }
-
-        // Descending chunks must be reversed.
-        if res == MergesortResult::Descending {
-            v[a..b].reverse();
-        }
-
-        chunks.push((a, b));
-    }
-
-    // All chunks are properly sorted.
-    // Now we just have to merge them together.
-    unsafe {
-        recurse(v.as_mut_ptr(), buf, &chunks, false, &is_less);
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::split_for_merge;
-    use rand::distributions::Uniform;
-    use rand::{thread_rng, Rng};
-
-    #[test]
-    fn test_split_for_merge() {
-        fn check(left: &[u32], right: &[u32]) {
-            let (l, r) = split_for_merge(left, right, &|&a, &b| a < b);
-            assert!(left[..l]
-                .iter()
-                .all(|&x| right[r..].iter().all(|&y| x <= y)));
-            assert!(right[..r].iter().all(|&x| left[l..].iter().all(|&y| x < y)));
-        }
-
-        check(&[1, 2, 2, 2, 2, 3], &[1, 2, 2, 2, 2, 3]);
-        check(&[1, 2, 2, 2, 2, 3], &[]);
-        check(&[], &[1, 2, 2, 2, 2, 3]);
-
-        let rng = &mut thread_rng();
-
-        for _ in 0..100 {
-            let limit: u32 = rng.gen_range(1..21);
-            let left_len: usize = rng.gen_range(0..20);
-            let right_len: usize = rng.gen_range(0..20);
-
-            let mut left = rng
-                .sample_iter(&Uniform::new(0, limit))
-                .take(left_len)
-                .collect::<Vec<_>>();
-            let mut right = rng
-                .sample_iter(&Uniform::new(0, limit))
-                .take(right_len)
-                .collect::<Vec<_>>();
-
-            left.sort();
-            right.sort();
-            check(&left, &right);
-        }
-    }
-}