use AsRef instead of Deref in NoAllocBufferSegments

Author: dwrensha

capnp/src/serialize/no_alloc_buffer_segments.rs

@@ -4,7 +4,6 @@ use crate::message::ReaderOptions;
 use crate::message::ReaderSegments;
 use crate::private::units::BYTES_PER_WORD;
 use crate::{Error, ErrorKind, Result};
-use core::ops::Deref;
 
 use super::SEGMENTS_COUNT_LIMIT;
 
@@ -147,19 +146,19 @@ impl<'b> NoAllocBufferSegments<&'b [u8]> {
     }
 }
 
-impl<T: Deref<Target = [u8]>> NoAllocBufferSegments<T> {
+impl<T: AsRef<[u8]>> NoAllocBufferSegments<T> {
     /// Reads a serialized message (including a segment table) from a buffer and takes ownership, without copying.
     /// The buffer is allowed to extend beyond the end of the message.
     ///
     /// ALIGNMENT: If the "unaligned" feature is enabled, then there are no alignment requirements on `buffer`.
     /// Otherwise, `buffer` must be 8-byte aligned (attempts to read the message will trigger errors).
     pub fn from_buffer(buffer: T, options: ReaderOptions) -> Result<Self> {
-        let segment_table_info = read_segment_table(&buffer, options)?;
+        let segment_table_info = read_segment_table(buffer.as_ref(), options)?;
         Ok(Self::from_segment_table(buffer, segment_table_info))
     }
 }
 
-impl<T: Deref<Target = [u8]>> ReaderSegments for NoAllocBufferSegments<T> {
+impl<T: AsRef<[u8]>> ReaderSegments for NoAllocBufferSegments<T> {
     fn get_segment(&self, idx: u32) -> Option<&[u8]> {
         // panic safety: we are doing a lot of `unwrap` here. We assume that underlying message slice
         // holds valid capnp message - we already verified slice in read_segment_table(),
@@ -170,13 +169,13 @@ impl<T: Deref<Target = [u8]>> ReaderSegments for NoAllocBufferSegments<T> {
         match self.segment_type {
             NoAllocBufferSegmentType::SingleSegment(start, end) => {
                 if idx == 0 {
-                    Some(&self.buffer[start..end])
+                    Some(&self.buffer.as_ref()[start..end])
                 } else {
                     None
                 }
             }
             NoAllocBufferSegmentType::MultipleSegments => {
-                let mut buf = &*self.buffer;
+                let mut buf = self.buffer.as_ref();
 
                 let segments_count = u32_to_segments_count(read_u32_le(&mut buf).unwrap()).unwrap();
 
@@ -197,7 +196,7 @@ impl<T: Deref<Target = [u8]>> ReaderSegments for NoAllocBufferSegments<T> {
                 let segment_length =
                     u32_to_segment_length_bytes(read_u32_le(&mut buf).unwrap()).unwrap();
 
-                Some(&self.buffer[segment_offset..(segment_offset + segment_length)])
+                Some(&self.buffer.as_ref()[segment_offset..(segment_offset + segment_length)])
             }
         }
     }
@@ -209,7 +208,7 @@ impl<T: Deref<Target = [u8]>> ReaderSegments for NoAllocBufferSegments<T> {
         match self.segment_type {
             NoAllocBufferSegmentType::SingleSegment { .. } => 1,
             NoAllocBufferSegmentType::MultipleSegments => {
-                u32_to_segments_count(read_u32_le(&mut &*self.buffer).unwrap()).unwrap()
+                u32_to_segments_count(read_u32_le(&mut self.buffer.as_ref()).unwrap()).unwrap()
             }
         }
     }