Removed impl Whence and assigned the libc values directly in the enum definition.

Author: ncaracci

src/unistd.rs

@@ -740,51 +740,37 @@ pub fn write(fd: RawFd, buf: &[u8]) -> Result<usize> {
 /// Directive that tells [`lseek`] and [`lseek64`] what the offset is relative to.
 /// [`lseek`]: ./fn.lseek.html
 /// [`lseek64`]: ./fn.lseek64.html
+#[repr(i32)]
 pub enum Whence {
     /// Specify an offset relative to the start of the file.
-    SeekSet,
+    SeekSet = libc::SEEK_SET,
     /// Specify an offset relative to the current file location.
-    SeekCur,
+    SeekCur = libc::SEEK_CUR,
     /// Specify an offset relative to the end of the file.
-    SeekEnd,
+    SeekEnd = libc::SEEK_END,
     /// Specify an offset relative to the next location in the file greater than or 
     /// equal to offset that contains some data. If offset points to
     /// some data, then the file offset is set to offset.
     #[cfg(any(target_os = "linux", target_os = "dragonfly", target_os = "freebsd"))]
-    SeekData,
+    SeekData = libc::SEEK_DATA,
     /// Specify an offset relative to the next hole in the file greater than
     /// or equal to offset. If offset points into the middle of a hole, then 
     /// the file offset should be set to offset. If there is no hole past offset,
     /// then the file offset should be adjusted to the end of the file (i.e., there
     /// is an implicit hole at the end of any file).
     #[cfg(any(target_os = "linux", target_os = "dragonfly", target_os = "freebsd"))]
-    SeekHole
-}
-
-impl Whence {
-    fn to_libc_type(&self) -> c_int {
-        match self {
-            &Whence::SeekSet => libc::SEEK_SET,
-            &Whence::SeekCur => libc::SEEK_CUR,
-            &Whence::SeekEnd => libc::SEEK_END,
-            #[cfg(any(target_os = "linux", target_os = "dragonfly", target_os = "freebsd"))]
-            &Whence::SeekData => libc::SEEK_DATA,
-            #[cfg(any(target_os = "linux", target_os = "dragonfly", target_os = "freebsd"))]
-            &Whence::SeekHole => libc::SEEK_HOLE
-        }
-    }
-
+    SeekHole = libc::SEEK_HOLE
 }
 
 pub fn lseek(fd: RawFd, offset: libc::off_t, whence: Whence) -> Result<libc::off_t> {
-    let res = unsafe { libc::lseek(fd, offset, whence.to_libc_type()) };
+    let res = unsafe { libc::lseek(fd, offset, whence as i32) };
 
     Errno::result(res).map(|r| r as libc::off_t)
 }
 
 #[cfg(any(target_os = "linux", target_os = "android"))]
 pub fn lseek64(fd: RawFd, offset: libc::off64_t, whence: Whence) -> Result<libc::off64_t> {
-    let res = unsafe { libc::lseek64(fd, offset, whence.to_libc_type()) };
+    let res = unsafe { libc::lseek64(fd, offset, whence as i32) };
 
     Errno::result(res).map(|r| r as libc::off64_t)
 }