Remove direct dependency on libc

Cargo.toml

@@ -22,9 +22,6 @@ serde = { version = "1.0.117", optional = true }
 serde_derive = { version = "1.0.117", optional = true }
 cfg-if = "1.0.0"
 
-[target.'cfg(not(windows))'.dependencies]
-libc = "0.2"
-
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3.9", features = ["winnt", "winbase", "processenv", "handleapi", "ntdef", "fileapi", "std"] }
 

src/clircle_unix.rs

@@ -3,13 +3,11 @@ use crate::{Clircle, Stdio};
 use std::convert::TryFrom;
 use std::fs::File;
 use std::io::{self, Seek};
+use std::os::fd::AsRawFd;
 use std::os::unix::fs::MetadataExt;
 use std::os::unix::io::{FromRawFd, IntoRawFd, RawFd};
 use std::{cmp, hash, ops};
 
-/// Re-export of libc
-pub use libc;
-
 /// Implementation of `Clircle` for Unix.
 #[derive(Debug)]
 pub struct UnixIdentifier {
@@ -80,9 +78,9 @@ impl TryFrom<Stdio> for UnixIdentifier {
 
     fn try_from(stdio: Stdio) -> Result<Self, Self::Error> {
         let fd = match stdio {
-            Stdio::Stdin => libc::STDIN_FILENO,
-            Stdio::Stdout => libc::STDOUT_FILENO,
-            Stdio::Stderr => libc::STDERR_FILENO,
+            Stdio::Stdin => io::stdin().as_raw_fd(),
+            Stdio::Stdout => io::stdout().as_raw_fd(),
+            Stdio::Stderr => io::stderr().as_raw_fd(),
         };
         // Safety: It is okay to create the file, because it won't be dropped later since the
         // `owns_fd` field is not set.

src/lib.rs

@@ -47,7 +47,7 @@
 cfg_if::cfg_if! {
     if #[cfg(unix)] {
         mod clircle_unix;
-        pub use clircle_unix::{libc, UnixIdentifier};
+        pub use clircle_unix::UnixIdentifier;
         /// Identifies a file. The type is aliased according to the target platform.
         pub type Identifier = UnixIdentifier;
     } else if #[cfg(windows)] {