From 50a2460eb12cb2688c15b275aaf963aa7d3f2717 Mon Sep 17 00:00:00 2001
From: Lachlan Deakin <ljdgit@gmail.com>
Date: Mon, 26 Feb 2024 12:49:02 +1100
Subject: [PATCH] Remove an unnecessary allocation in `IndicesIterator`

---
 CHANGELOG.md                                   |  3 +++
 Cargo.toml                                     |  2 +-
 src/array_subset/iterators/indices_iterator.rs | 18 ++++++------------
 3 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5a41be4e..7ef8ae47 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
  - Disabled `blosc` codec partial decoding
 
+### Fixed
+ - Remove an unnecessary allocation in `IndicesIterator`
+
 ## [0.12.1] - 2024-02-24
 
 ### Added
diff --git a/Cargo.toml b/Cargo.toml
index d25ca130..a64400c8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "zarrs"
-version = "0.12.1"
+version = "0.12.2"
 authors = ["Lachlan Deakin <ljdgit@gmail.com>"]
 edition = "2021"
 rust-version = "1.71"
diff --git a/src/array_subset/iterators/indices_iterator.rs b/src/array_subset/iterators/indices_iterator.rs
index 858e1f0f..44cd3a5a 100644
--- a/src/array_subset/iterators/indices_iterator.rs
+++ b/src/array_subset/iterators/indices_iterator.rs
@@ -142,12 +142,9 @@ impl Iterator for IndicesIterator<'_> {
     type Item = ArrayIndices;
 
     fn next(&mut self) -> Option<Self::Item> {
-        let indices = std::iter::zip(
-            unravel_index(self.index_front, self.subset.shape()).iter(),
-            self.subset.start(),
-        )
-        .map(|(index, start)| index + start)
-        .collect::<Vec<_>>();
+        let mut indices = unravel_index(self.index_front, self.subset.shape());
+        std::iter::zip(indices.iter_mut(), self.subset.start())
+            .for_each(|(index, start)| *index += start);
 
         if self.index_front < self.index_back {
             self.index_front += 1;
@@ -166,12 +163,9 @@ impl DoubleEndedIterator for IndicesIterator<'_> {
     fn next_back(&mut self) -> Option<Self::Item> {
         if self.index_back > self.index_front {
             self.index_back -= 1;
-            let indices = std::iter::zip(
-                unravel_index(self.index_back, self.subset.shape()).iter(),
-                self.subset.start(),
-            )
-            .map(|(index, start)| index + start)
-            .collect::<Vec<_>>();
+            let mut indices = unravel_index(self.index_back, self.subset.shape());
+            std::iter::zip(indices.iter_mut(), self.subset.start())
+                .for_each(|(index, start)| *index += start);
             Some(indices)
         } else {
             None