Remove trait_upcasting requirement

Author: bugadani

espflash/src/connection.rs

@@ -1,8 +1,4 @@
-use std::{
-    io::{BufWriter, Read},
-    thread::sleep,
-    time::Duration,
-};
+use std::{io::BufWriter, thread::sleep, time::Duration};
 
 use binread::{io::Cursor, BinRead, BinReaderExt};
 use bytemuck::{Pod, Zeroable};
@@ -263,8 +259,7 @@ impl Connection {
     pub(crate) fn read(&mut self, len: usize) -> Result<Option<Vec<u8>>, Error> {
         let mut tmp = Vec::with_capacity(1024);
         loop {
-            self.decoder
-                .decode(self.serial.serial_port_mut() as &mut dyn Read, &mut tmp)?;
+            self.decoder.decode(&mut self.serial, &mut tmp)?;
             if tmp.len() >= len {
                 return Ok(Some(tmp));
             }

espflash/src/interface.rs

@@ -1,3 +1,5 @@
+use std::io::Read;
+
 use serialport::SerialPort;
 
 #[cfg(feature = "raspberry")]
@@ -79,3 +81,11 @@ impl Interface {
         self.serial_port.as_mut()
     }
 }
+
+// Note(dbuga): this impl is necessary because using `dyn SerialPort` as `dyn Read`
+// requires trait_upcasting which isn't stable yet.
+impl Read for Interface {
+    fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
+        self.serial_port.read(buf)
+    }
+}

espflash/src/lib.rs

@@ -1,6 +1,3 @@
-#![feature(trait_upcasting)]
-#![allow(incomplete_features)] // trait_upcasting
-
 pub use chip::Chip;
 pub use cli::config::Config;
 pub use elf::{FlashFrequency, FlashMode};