Vendor things

third-party/vendor/indexmap/src/rayon/mod.rs

@@ -0,0 +1,29 @@
+#![cfg_attr(docsrs, doc(cfg(feature = "rayon")))]
+
+use rayon::prelude::*;
+
+use alloc::collections::LinkedList;
+
+use crate::vec::Vec;
+
+pub mod map;
+pub mod set;
+
+// This form of intermediate collection is also how Rayon collects `HashMap`.
+// Note that the order will also be preserved!
+fn collect<I: IntoParallelIterator>(iter: I) -> LinkedList<Vec<I::Item>> {
+    iter.into_par_iter()
+        .fold(Vec::new, |mut vec, elem| {
+            vec.push(elem);
+            vec
+        })
+        .map(|vec| {
+            let mut list = LinkedList::new();
+            list.push_back(vec);
+            list
+        })
+        .reduce(LinkedList::new, |mut list1, mut list2| {
+            list1.append(&mut list2);
+            list1
+        })
+}