[io] Add specialized read_exact and write_all for slices

Author: Conaclos

embedded-io-async/src/impls/slice_mut.rs

@@ -24,4 +24,13 @@ impl Write for &mut [u8] {
         *self = b;
         Ok(amt)
     }
+
+    #[inline]
+    async fn write_all(&mut self, buf: &[u8]) -> Result<(), Self::Error> {
+        if self.len() < buf.len() {
+            return Err(SliceWriteError::Full);
+        }
+        self.write(buf).await?;
+        Ok(())
+    }
 }

embedded-io-async/src/impls/slice_ref.rs

@@ -22,6 +22,17 @@ impl Read for &[u8] {
         *self = b;
         Ok(amt)
     }
+
+    async fn read_exact(
+        &mut self,
+        buf: &mut [u8],
+    ) -> Result<(), embedded_io::ReadExactError<Self::Error>> {
+        if self.len() < buf.len() {
+            return Err(crate::ReadExactError::UnexpectedEof);
+        }
+        self.read(buf).await?;
+        Ok(())
+    }
 }
 
 impl BufRead for &[u8] {

embedded-io/src/impls/slice_mut.rs

@@ -42,6 +42,15 @@ impl Write for &mut [u8] {
         Ok(amt)
     }
 
+    #[inline]
+    fn write_all(&mut self, buf: &[u8]) -> Result<(), Self::Error> {
+        if self.len() < buf.len() {
+            return Err(SliceWriteError::Full);
+        }
+        self.write(buf)?;
+        Ok(())
+    }
+
     #[inline]
     fn flush(&mut self) -> Result<(), Self::Error> {
         Ok(())

embedded-io/src/impls/slice_ref.rs

@@ -26,6 +26,15 @@ impl Read for &[u8] {
         *self = b;
         Ok(amt)
     }
+
+    #[inline]
+    fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), crate::ReadExactError<Self::Error>> {
+        if self.len() < buf.len() {
+            return Err(crate::ReadExactError::UnexpectedEof);
+        }
+        self.read(buf)?;
+        Ok(())
+    }
 }
 
 impl BufRead for &[u8] {