aboutsummaryrefslogtreecommitdiff
path: root/vendor/rayon/src/collections/mod.rs
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/rayon/src/collections/mod.rs')
-rw-r--r--vendor/rayon/src/collections/mod.rs84
1 files changed, 84 insertions, 0 deletions
diff --git a/vendor/rayon/src/collections/mod.rs b/vendor/rayon/src/collections/mod.rs
new file mode 100644
index 0000000..3c99f32
--- /dev/null
+++ b/vendor/rayon/src/collections/mod.rs
@@ -0,0 +1,84 @@
+//! Parallel iterator types for [standard collections][std::collections]
+//!
+//! You will rarely need to interact with this module directly unless you need
+//! to name one of the iterator types.
+//!
+//! [std::collections]: https://doc.rust-lang.org/stable/std/collections/
+
+/// Convert an iterable collection into a parallel iterator by first
+/// collecting into a temporary `Vec`, then iterating that.
+macro_rules! into_par_vec {
+ ($t:ty => $iter:ident<$($i:tt),*>, impl $($args:tt)*) => {
+ impl $($args)* IntoParallelIterator for $t {
+ type Item = <$t as IntoIterator>::Item;
+ type Iter = $iter<$($i),*>;
+
+ fn into_par_iter(self) -> Self::Iter {
+ use std::iter::FromIterator;
+ $iter { inner: Vec::from_iter(self).into_par_iter() }
+ }
+ }
+ };
+}
+
+pub mod binary_heap;
+pub mod btree_map;
+pub mod btree_set;
+pub mod hash_map;
+pub mod hash_set;
+pub mod linked_list;
+pub mod vec_deque;
+
+use self::drain_guard::DrainGuard;
+
+mod drain_guard {
+ use crate::iter::ParallelDrainRange;
+ use std::mem;
+ use std::ops::RangeBounds;
+
+ /// A proxy for draining a collection by converting to a `Vec` and back.
+ ///
+ /// This is used for draining `BinaryHeap` and `VecDeque`, which both have
+ /// zero-allocation conversions to/from `Vec`, though not zero-cost:
+ /// - `BinaryHeap` will heapify from `Vec`, but at least that will be empty.
+ /// - `VecDeque` has to shift items to offset 0 when converting to `Vec`.
+ #[allow(missing_debug_implementations)]
+ pub(super) struct DrainGuard<'a, T, C: From<Vec<T>>> {
+ collection: &'a mut C,
+ vec: Vec<T>,
+ }
+
+ impl<'a, T, C> DrainGuard<'a, T, C>
+ where
+ C: Default + From<Vec<T>>,
+ Vec<T>: From<C>,
+ {
+ pub(super) fn new(collection: &'a mut C) -> Self {
+ Self {
+ // Temporarily steal the inner `Vec` so we can drain in place.
+ vec: Vec::from(mem::take(collection)),
+ collection,
+ }
+ }
+ }
+
+ impl<'a, T, C: From<Vec<T>>> Drop for DrainGuard<'a, T, C> {
+ fn drop(&mut self) {
+ // Restore the collection from the `Vec` with its original capacity.
+ *self.collection = C::from(mem::take(&mut self.vec));
+ }
+ }
+
+ impl<'a, T, C> ParallelDrainRange<usize> for &'a mut DrainGuard<'_, T, C>
+ where
+ T: Send,
+ C: From<Vec<T>>,
+ {
+ type Iter = crate::vec::Drain<'a, T>;
+ type Item = T;
+
+ fn par_drain<R: RangeBounds<usize>>(self, range: R) -> Self::Iter {
+ self.vec.par_drain(range)
+ }
+ }
+}