[arrow-rs] branch master updated: impl `Default` for `arrow_buffer::buffer::MutableBuffer` (#4619)

[tustvold]

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tustvold pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/arrow-rs.git


The following commit(s) were added to refs/heads/master by this push:
     new a016654cfb impl `Default` for `arrow_buffer::buffer::MutableBuffer` 
(#4619)
a016654cfb is described below

commit a016654cfb90c6d7fa5c595cfeffd8fcbeca7f9d
Author: Matthijs Brobbel <m1brob...@gmail.com>
AuthorDate: Wed Aug 2 10:46:35 2023 +0200

    impl `Default` for `arrow_buffer::buffer::MutableBuffer` (#4619)
    
    * impl `Default` for `MutableBuffer`
    
    * Add a test
---
 arrow-buffer/src/buffer/mutable.rs | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arrow-buffer/src/buffer/mutable.rs 
b/arrow-buffer/src/buffer/mutable.rs
index 0d2d2ed751..8655bdb89c 100644
--- a/arrow-buffer/src/buffer/mutable.rs
+++ b/arrow-buffer/src/buffer/mutable.rs
@@ -650,6 +650,12 @@ impl MutableBuffer {
     }
 }
 
+impl Default for MutableBuffer {
+    fn default() -> Self {
+        Self::with_capacity(0)
+    }
+}
+
 impl std::ops::Deref for MutableBuffer {
     type Target = [u8];
 
@@ -777,6 +783,19 @@ mod tests {
         assert!(buf.is_empty());
     }
 
+    #[test]
+    fn test_mutable_default() {
+        let buf = MutableBuffer::default();
+        assert_eq!(0, buf.capacity());
+        assert_eq!(0, buf.len());
+        assert!(buf.is_empty());
+
+        let mut buf = MutableBuffer::default();
+        buf.extend_from_slice(b"hello");
+        assert_eq!(5, buf.len());
+        assert_eq!(b"hello", buf.as_slice());
+    }
+
     #[test]
     fn test_mutable_extend_from_slice() {
         let mut buf = MutableBuffer::new(100);