Implement AsRawFd for PollFd

Implement the trait on PollFd, providing an `as_raw_fd()` accessor to
get the RawFd associated with the PollFd.

Subsumes #1147, #1286.  Closes #1146.

Test: `cargo test --test test test_pollfd_fd`

1 files changed, 7 insertions, 1 deletions

diff --git a/src/poll.rs b/src/poll.rs
index e814337a..0eaf7e1d 100644
--- a/src/poll.rs
+++ b/src/poll.rs
@@ -3,7 +3,7 @@
 use crate::sys::time::TimeSpec;
 #[cfg(any(target_os = "android", target_os = "dragonfly", target_os = "freebsd", target_os = "linux"))]
 use crate::sys::signal::SigSet;
-use std::os::unix::io::RawFd;
+use std::os::unix::io::{AsRawFd, RawFd};
 
 use crate::Result;
 use crate::errno::Errno;
@@ -41,6 +41,12 @@ impl PollFd {
     }
 }
 
+impl AsRawFd for PollFd {
+    fn as_raw_fd(&self) -> RawFd {
+        self.pollfd.fd
+    }
+}
+
 libc_bitflags! {
     /// These flags define the different events that can be monitored by `poll` and `ppoll`
     pub struct PollFlags: libc::c_short {