edition: Use dyn syntax for trait objects

Found by running: `cargo rustc -- -D bare_trait_objects`

Bare trait objects like `&Trait` and `Box<Trait>` are soft-deprecated in
2018 edition and will start warning at some point.

As part of this, I replaced `Box<Trait + 'static>` with `Box<dyn Trait>`
because the 'static bound is implied for boxed trait objects.

TEST=cargo check --all-features
TEST=cargo check --target aarch64-unknown-linux-gnu
TEST=local kokoro

Change-Id: I41c4f13530bece8a34a8ed1c1afd7035b8f86f19
Reviewed-on: https://chromium-review.googlesource.com/1513059
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: David Tolnay <dtolnay@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: David Tolnay <dtolnay@chromium.org>

1 files changed, 6 insertions, 5 deletions

diff --git a/devices/src/virtio/wl.rs b/devices/src/virtio/wl.rs
index a9498fe..870b5ea 100644
--- a/devices/src/virtio/wl.rs
+++ b/devices/src/virtio/wl.rs
@@ -32,6 +32,7 @@ use std::cell::RefCell;
 use std::collections::btree_map::Entry;
 use std::collections::{BTreeMap as Map, BTreeSet as Set, VecDeque};
 use std::convert::From;
+use std::error::Error as StdError;
 use std::ffi::CStr;
 use std::fmt::{self, Display};
 use std::fs::File;
@@ -645,7 +646,7 @@ enum WlResp<'a> {
     VfdHup {
         id: u32,
     },
-    Err(Box<std::error::Error>),
+    Err(Box<dyn StdError>),
     OutOfMemory,
     InvalidId,
     InvalidType,
@@ -891,11 +892,11 @@ impl WlVfd {
     }
 
     // The FD that is used for polling for events on this VFD.
-    fn poll_fd(&self) -> Option<&AsRawFd> {
-        self.socket
+    fn poll_fd(&self) -> Option<&dyn AsRawFd> {
+        self.socket.as_ref().map(|s| s as &dyn AsRawFd).or(self
+            .local_pipe
             .as_ref()
-            .map(|s| s as &AsRawFd)
-            .or(self.local_pipe.as_ref().map(|&(_, ref p)| p as &AsRawFd))
+            .map(|&(_, ref p)| p as &dyn AsRawFd))
     }
 
     // Sends data/files from the guest to the host over this VFD.