Upgrade rust/crates/itertools to 0.10.0 am: 6f798715de am: b1d1cd1ee8 am: e7475af424 am: 16514b8f27android-mainline-12.0.0_r99android-mainline-12.0.0_r98android-mainline-12.0.0_r97android-mainline-12.0.0_r96android-mainline-12.0.0_r95android-mainline-12.0.0_r94android-mainline-12.0.0_r93android-mainline-12.0.0_r92android-mainline-12.0.0_r91android-mainline-12.0.0_r90android-mainline-12.0.0_r9android-mainline-12.0.0_r89android-mainline-12.0.0_r88android-mainline-12.0.0_r87android-mainline-12.0.0_r86android-mainline-12.0.0_r85android-mainline-12.0.0_r84android-mainline-12.0.0_r83android-mainline-12.0.0_r82android-mainline-12.0.0_r81android-mainline-12.0.0_r80android-mainline-12.0.0_r8android-mainline-12.0.0_r79android-mainline-12.0.0_r78android-mainline-12.0.0_r77android-mainline-12.0.0_r76android-mainline-12.0.0_r75android-mainline-12.0.0_r74android-mainline-12.0.0_r73android-mainline-12.0.0_r72android-mainline-12.0.0_r71android-mainline-12.0.0_r70android-mainline-12.0.0_r7android-mainline-12.0.0_r69android-mainline-12.0.0_r68android-mainline-12.0.0_r67android-mainline-12.0.0_r66android-mainline-12.0.0_r65android-mainline-12.0.0_r64android-mainline-12.0.0_r63android-mainline-12.0.0_r62android-mainline-12.0.0_r61android-mainline-12.0.0_r60android-mainline-12.0.0_r6android-mainline-12.0.0_r59android-mainline-12.0.0_r58android-mainline-12.0.0_r57android-mainline-12.0.0_r56android-mainline-12.0.0_r53android-mainline-12.0.0_r52android-mainline-12.0.0_r51android-mainline-12.0.0_r50android-mainline-12.0.0_r5android-mainline-12.0.0_r49android-mainline-12.0.0_r48android-mainline-12.0.0_r47android-mainline-12.0.0_r46android-mainline-12.0.0_r45android-mainline-12.0.0_r44android-mainline-12.0.0_r43android-mainline-12.0.0_r42android-mainline-12.0.0_r41android-mainline-12.0.0_r40android-mainline-12.0.0_r39android-mainline-12.0.0_r38android-mainline-12.0.0_r37android-mainline-12.0.0_r35android-mainline-12.0.0_r34android-mainline-12.0.0_r33android-mainline-12.0.0_r32android-mainline-12.0.0_r31android-mainline-12.0.0_r30android-mainline-12.0.0_r3android-mainline-12.0.0_r29android-mainline-12.0.0_r28android-mainline-12.0.0_r27android-mainline-12.0.0_r26android-mainline-12.0.0_r25android-mainline-12.0.0_r24android-mainline-12.0.0_r23android-mainline-12.0.0_r22android-mainline-12.0.0_r21android-mainline-12.0.0_r20android-mainline-12.0.0_r2android-mainline-12.0.0_r19android-mainline-12.0.0_r18android-mainline-12.0.0_r17android-mainline-12.0.0_r16android-mainline-12.0.0_r15android-mainline-12.0.0_r14android-mainline-12.0.0_r13android-mainline-12.0.0_r126android-mainline-12.0.0_r125android-mainline-12.0.0_r124android-mainline-12.0.0_r123android-mainline-12.0.0_r122android-mainline-12.0.0_r121android-mainline-12.0.0_r120android-mainline-12.0.0_r12android-mainline-12.0.0_r119android-mainline-12.0.0_r118android-mainline-12.0.0_r117android-mainline-12.0.0_r116android-mainline-12.0.0_r115android-mainline-12.0.0_r114android-mainline-12.0.0_r113android-mainline-12.0.0_r110android-mainline-12.0.0_r11android-mainline-12.0.0_r109android-mainline-12.0.0_r108android-mainline-12.0.0_r107android-mainline-12.0.0_r106android-mainline-12.0.0_r105android-mainline-12.0.0_r104android-mainline-12.0.0_r103android-mainline-12.0.0_r102android-mainline-12.0.0_r101android-mainline-12.0.0_r100android-mainline-12.0.0_r10android-mainline-12.0.0_r1aml_wif_311811030aml_tz3_311312010aml_tet_311811050aml_sdk_311710000aml_pco_311011000aml_mpr_311911090aml_doc_310851020android12-mainline-wifi-releaseandroid12-mainline-tethering-releaseandroid12-mainline-statsd-releaseandroid12-mainline-sdkext-releaseandroid12-mainline-resolv-releaseandroid12-mainline-permission-releaseandroid12-mainline-neuralnetworks-releaseandroid12-mainline-networkstack-releaseandroid12-mainline-mediaprovider-releaseandroid12-mainline-media-swcodec-releaseandroid12-mainline-media-releaseandroid12-mainline-ipsec-releaseandroid12-mainline-extservices-releaseandroid12-mainline-documentsui-releaseandroid12-mainline-conscrypt-releaseandroid12-mainline-cellbroadcast-releaseandroid12-mainline-captiveportallogin-releaseandroid12-mainline-art-releaseandroid12-mainline-adbd-release

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/itertools/+/1662678

Change-Id: I56b01b4f2ed1b374372c6c57e71f89e0581df6b7

1 files changed, 34 insertions, 2 deletions

diff --git a/src/unique_impl.rs b/src/unique_impl.rs
index cf8675c..14c14fc 100644
--- a/src/unique_impl.rs
+++ b/src/unique_impl.rs
@@ -54,7 +54,7 @@ impl<I, V, F> Iterator for UniqueBy<I, V, F>
 {
     type Item = I::Item;
 
-    fn next(&mut self) -> Option<I::Item> {
+    fn next(&mut self) -> Option<Self::Item> {
         while let Some(v) = self.iter.next() {
             let key = (self.f)(&v);
             if self.used.insert(key, ()).is_none() {
@@ -76,13 +76,29 @@ impl<I, V, F> Iterator for UniqueBy<I, V, F>
     }
 }
 
+impl<I, V, F> DoubleEndedIterator for UniqueBy<I, V, F>
+    where I: DoubleEndedIterator,
+          V: Eq + Hash,
+          F: FnMut(&I::Item) -> V
+{
+    fn next_back(&mut self) -> Option<Self::Item> {
+        while let Some(v) = self.iter.next_back() {
+            let key = (self.f)(&v);
+            if self.used.insert(key, ()).is_none() {
+                return Some(v);
+            }
+        }
+        None
+    }
+}
+
 impl<I> Iterator for Unique<I>
     where I: Iterator,
           I::Item: Eq + Hash + Clone
 {
     type Item = I::Item;
 
-    fn next(&mut self) -> Option<I::Item> {
+    fn next(&mut self) -> Option<Self::Item> {
         while let Some(v) = self.iter.iter.next() {
             if let Entry::Vacant(entry) = self.iter.used.entry(v) {
                 let elt = entry.key().clone();
@@ -104,6 +120,22 @@ impl<I> Iterator for Unique<I>
     }
 }
 
+impl<I> DoubleEndedIterator for Unique<I>
+    where I: DoubleEndedIterator,
+          I::Item: Eq + Hash + Clone
+{
+    fn next_back(&mut self) -> Option<Self::Item> {
+        while let Some(v) = self.iter.iter.next_back() {
+            if let Entry::Vacant(entry) = self.iter.used.entry(v) {
+                let elt = entry.key().clone();
+                entry.insert(());
+                return Some(elt);
+            }
+        }
+        None
+    }
+}
+
 /// An iterator adapter to filter out duplicate elements.
 ///
 /// See [`.unique()`](../trait.Itertools.html#method.unique) for more information.