From 74889255f143fc091d8ea4baebb122125e7b64f7 Mon Sep 17 00:00:00 2001
From: Matthijs Brobbel <m1brobbel@gmail.com>
Date: Wed, 2 Aug 2023 13:39:45 +0200
Subject: [PATCH] impl `FromIterator` for `MutableBuffer` (#4624)

---
 arrow-buffer/src/buffer/mutable.rs | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arrow-buffer/src/buffer/mutable.rs b/arrow-buffer/src/buffer/mutable.rs
index 8655bdb89c55..0177582b0b97 100644
--- a/arrow-buffer/src/buffer/mutable.rs
+++ b/arrow-buffer/src/buffer/mutable.rs
@@ -771,6 +771,14 @@ impl std::iter::FromIterator<bool> for MutableBuffer {
     }
 }
 
+impl<T: ArrowNativeType> std::iter::FromIterator<T> for MutableBuffer {
+    fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self {
+        let mut buffer = Self::default();
+        buffer.extend_from_iter(iter.into_iter());
+        buffer
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -985,4 +993,11 @@ mod tests {
         let mut buffer = MutableBuffer::new(0);
         buffer.set_null_bits(1, usize::MAX);
     }
+
+    #[test]
+    fn from_iter() {
+        let buffer = [1u16, 2, 3, 4].into_iter().collect::<MutableBuffer>();
+        assert_eq!(buffer.len(), 4 * mem::size_of::<u16>());
+        assert_eq!(buffer.as_slice(), &[1, 0, 2, 0, 3, 0, 4, 0]);
+    }
 }