return type

src/sys/eventfd.rs

@@ -61,7 +61,7 @@ impl EventFd {
     /// [`EventFd::write`] with `value`.
     pub fn write(&self, value: eventfd_t) -> Result<usize> {
         let res = unsafe { libc::eventfd_write(self.0.as_raw_fd(), value) };
-        Errno::result(res)
+        Errno::result(res).map(|res| res as usize)
     }
     // Reads the value from the file descriptor.
     pub fn read(&self) -> Result<eventfd_t> {