From 244e9b0ed13e312ad7ed16be259d7396d17a3c4f Mon Sep 17 00:00:00 2001
From: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Date: Mon, 14 Apr 2025 14:47:46 +0200
Subject: [PATCH 1/3] Implement `Default` for `ScalarBuffer`

---
 arrow-buffer/src/buffer/scalar.rs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arrow-buffer/src/buffer/scalar.rs b/arrow-buffer/src/buffer/scalar.rs
index 94dd7bcfc22e..8a47b8c44cea 100644
--- a/arrow-buffer/src/buffer/scalar.rs
+++ b/arrow-buffer/src/buffer/scalar.rs
@@ -48,6 +48,13 @@ pub struct ScalarBuffer<T: ArrowNativeType> {
     phantom: PhantomData<T>,
 }
 
+impl<T: ArrowNativeType> Default for ScalarBuffer<T> {
+    #[inline]
+    fn default() -> Self {
+        Self::from(vec![])
+    }
+}
+
 impl<T: ArrowNativeType> std::fmt::Debug for ScalarBuffer<T> {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         f.debug_tuple("ScalarBuffer").field(&self.as_ref()).finish()

From abb649876cf6bc314f25db6210fa3c6e23778110 Mon Sep 17 00:00:00 2001
From: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Date: Mon, 14 Apr 2025 15:25:06 +0200
Subject: [PATCH 2/3] `impl Default for Buffer`

---
 arrow-buffer/src/buffer/immutable.rs | 7 +++++++
 arrow-buffer/src/buffer/scalar.rs    | 5 ++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/arrow-buffer/src/buffer/immutable.rs b/arrow-buffer/src/buffer/immutable.rs
index fd145ce2306e..5d229a4967b0 100644
--- a/arrow-buffer/src/buffer/immutable.rs
+++ b/arrow-buffer/src/buffer/immutable.rs
@@ -82,6 +82,13 @@ pub struct Buffer {
     length: usize,
 }
 
+impl Default for Buffer {
+    #[inline]
+    fn default() -> Self {
+        MutableBuffer::default().into()
+    }
+}
+
 impl PartialEq for Buffer {
     fn eq(&self, other: &Self) -> bool {
         self.as_slice().eq(other.as_slice())
diff --git a/arrow-buffer/src/buffer/scalar.rs b/arrow-buffer/src/buffer/scalar.rs
index 8a47b8c44cea..5c65d4cd587b 100644
--- a/arrow-buffer/src/buffer/scalar.rs
+++ b/arrow-buffer/src/buffer/scalar.rs
@@ -51,7 +51,10 @@ pub struct ScalarBuffer<T: ArrowNativeType> {
 impl<T: ArrowNativeType> Default for ScalarBuffer<T> {
     #[inline]
     fn default() -> Self {
-        Self::from(vec![])
+        Self {
+            buffer: Default::default(),
+            phantom: Default::default(),
+        }
     }
 }
 

From b97c042c72dd7861a708269cb96392f31fb904d7 Mon Sep 17 00:00:00 2001
From: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Date: Mon, 14 Apr 2025 15:27:07 +0200
Subject: [PATCH 3/3] Auto-derive Default

---
 arrow-buffer/src/buffer/scalar.rs | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/arrow-buffer/src/buffer/scalar.rs b/arrow-buffer/src/buffer/scalar.rs
index 5c65d4cd587b..e0a59a3e0312 100644
--- a/arrow-buffer/src/buffer/scalar.rs
+++ b/arrow-buffer/src/buffer/scalar.rs
@@ -41,23 +41,13 @@ use std::ops::Deref;
 /// let sliced = buffer.slice(1, 2);
 /// assert_eq!(&sliced, &[2, 3]);
 /// ```
-#[derive(Clone)]
+#[derive(Clone, Default)]
 pub struct ScalarBuffer<T: ArrowNativeType> {
     /// Underlying data buffer
     buffer: Buffer,
     phantom: PhantomData<T>,
 }
 
-impl<T: ArrowNativeType> Default for ScalarBuffer<T> {
-    #[inline]
-    fn default() -> Self {
-        Self {
-            buffer: Default::default(),
-            phantom: Default::default(),
-        }
-    }
-}
-
 impl<T: ArrowNativeType> std::fmt::Debug for ScalarBuffer<T> {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         f.debug_tuple("ScalarBuffer").field(&self.as_ref()).finish()