1 files changed, 48 insertions, 0 deletions
diff --git a/third_party/rust/rayon/src/string.rs b/third_party/rust/rayon/src/string.rs
new file mode 100644
index 0000000000..91e69f9a3c
--- /dev/null
+++ b/third_party/rust/rayon/src/string.rs
@@ -0,0 +1,48 @@
+//! This module contains the parallel iterator types for owned strings
+//! (`String`). You will rarely need to interact with it directly
+//! unless you have need to name one of the iterator types.
+
+use crate::iter::plumbing::*;
+use crate::math::simplify_range;
+use crate::prelude::*;
+use std::ops::{Range, RangeBounds};
+
+impl<'a> ParallelDrainRange<usize> for &'a mut String {
+    type Iter = Drain<'a>;
+    type Item = char;
+
+    fn par_drain<R: RangeBounds<usize>>(self, range: R) -> Self::Iter {
+        Drain {
+            range: simplify_range(range, self.len()),
+            string: self,
+        }
+    }
+}
+
+/// Draining parallel iterator that moves a range of characters out of a string,
+/// but keeps the total capacity.
+#[derive(Debug)]
+pub struct Drain<'a> {
+    string: &'a mut String,
+    range: Range<usize>,
+}
+
+impl<'a> ParallelIterator for Drain<'a> {
+    type Item = char;
+
+    fn drive_unindexed<C>(self, consumer: C) -> C::Result
+    where
+        C: UnindexedConsumer<Self::Item>,
+    {
+        self.string[self.range.clone()]
+            .par_chars()
+            .drive_unindexed(consumer)
+    }
+}
+
+impl<'a> Drop for Drain<'a> {
+    fn drop(&mut self) {
+        // Remove the drained range.
+        self.string.drain(self.range.clone());
+    }
+}