Fix warnings on Rust 1.37.0

* Replace obsolete range syntax "..." with inclusive range "..="
* Use dyn Trait syntax instead of Box<Trait>
* Raise MSRV to 1.27.0 (for dyn Trait syntax)
* Raise MSRV to 1.31.0 (because of rand)

tempfile pulls in rand, and rand pulls in fuchsia-cprng, which requires
1.31.0.  Why rand pulls in fuchsia-cprng I don't know.  It's specified
as a target-specific dependency, but Cargo tries to build it anyway
(only on Linux, not on FreeBSD or OSX).  A bug in Cargo 1.27.0?

9 files changed, 56 insertions, 56 deletions

diff --git a/.cirrus.yml b/.cirrus.yml
index eca3d347..db1a90ad 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -14,7 +14,7 @@ task:
   setup_script:
     - pkg install -y curl
     - curl https://sh.rustup.rs -sSf --output rustup.sh
-    - sh rustup.sh -y --default-toolchain 1.25.0
+    - sh rustup.sh -y --default-toolchain 1.31.0
     - $HOME/.cargo/bin/rustup target add i686-unknown-freebsd
   amd64_test_script:
     - . $HOME/.cargo/env
diff --git a/.travis.yml b/.travis.yml
index a667201a..917105e6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -18,71 +18,71 @@ matrix:
     # week.  Additionally they're moved to the front of the line to get them in
     # the Travis OS X build queue first.
     - env: TARGET="aarch64-apple-ios;armv7-apple-ios;armv7s-apple-ios;i386-apple-ios;x86_64-apple-ios" DISABLE_TESTS=1
-      rust: 1.25.0
+      rust: 1.31.0
       os: osx
 
     # Mac builds
     # These are also moved to be first because they wait in a long queue with
     # Travis
     - env: TARGET=i686-apple-darwin
-      rust: 1.25.0
+      rust: 1.31.0
       os: osx
     - env: TARGET=x86_64-apple-darwin
-      rust: 1.25.0
+      rust: 1.31.0
       os: osx
 
     # Android
     - env: TARGET=aarch64-linux-android DISABLE_TESTS=1
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=arm-linux-androideabi DISABLE_TESTS=1
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=armv7-linux-androideabi DISABLE_TESTS=1
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=i686-linux-android DISABLE_TESTS=1
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=x86_64-linux-android DISABLE_TESTS=1
-      rust: 1.25.0
+      rust: 1.31.0
 
     # Linux
     - env: TARGET=aarch64-unknown-linux-gnu
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=arm-unknown-linux-gnueabi
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=arm-unknown-linux-musleabi DISABLE_TESTS=1
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=armv7-unknown-linux-gnueabihf
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=i686-unknown-linux-gnu
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=i686-unknown-linux-musl
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=mips-unknown-linux-gnu
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=mips64-unknown-linux-gnuabi64
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=mips64el-unknown-linux-gnuabi64
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=mipsel-unknown-linux-gnu
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=powerpc-unknown-linux-gnu DISABLE_TESTS=1
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=powerpc64-unknown-linux-gnu
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=powerpc64le-unknown-linux-gnu
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=s390x-unknown-linux-gnu DISABLE_TESTS=1
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=x86_64-unknown-linux-gnu
-      rust: 1.25.0
+      rust: 1.31.0
     - env: TARGET=x86_64-unknown-linux-musl
-      rust: 1.25.0
+      rust: 1.31.0
 
     # *BSD
     # FreeBSD i686 and x86_64 use Cirrus instead of Travis
     # - env: TARGET=i686-unknown-freebsd DISABLE_TESTS=1
     # - env: TARGET=x86_64-unknown-freebsd DISABLE_TESTS=1
     - env: TARGET=x86_64-unknown-netbsd DISABLE_TESTS=1
-      rust: 1.25.0
+      rust: 1.31.0
 
     # Make sure stable is always working too
     - env: TARGET=x86_64-unknown-linux-gnu
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 777b4d98..863216b7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,8 +19,9 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ### Changed
 - Support for `ifaddrs` now present when building for Android.
   ([#1077](https://github.com/nix-rust/nix/pull/1077))
-- Minimum supported Rust version is now 1.25.0 
+- Minimum supported Rust version is now 1.31.0
   ([#1035](https://github.com/nix-rust/nix/pull/1035))
+  ([#1095](https://github.com/nix-rust/nix/pull/1095))
 - Now functions `statfs()` and `fstatfs()` return result with `Statfs` wrapper
   ([#928](https://github.com/nix-rust/nix/pull/928))
 
diff --git a/README.md b/README.md
index 41ee98a5..8d8fd729 100644
--- a/README.md
+++ b/README.md
@@ -83,7 +83,7 @@ Tier 2:
 
 ## Usage
 
-`nix` requires Rust 1.25.0 or newer.
+`nix` requires Rust 1.31.0 or newer.
 
 To use `nix`, first add this to your `Cargo.toml`:
 
diff --git a/src/features.rs b/src/features.rs
index 7797aa46..76cdfd3a 100644
--- a/src/features.rs
+++ b/src/features.rs
@@ -39,7 +39,7 @@ mod os {
                 b'.' | b'-' => {
                     curr += 1;
                 }
-                b'0'...b'9' => {
+                b'0'..=b'9' => {
                     match curr {
                         0 => digit(&mut major, b),
                         1 => digit(&mut minor, b),
diff --git a/src/sched.rs b/src/sched.rs
index 064fc29d..67188c57 100644
--- a/src/sched.rs
+++ b/src/sched.rs
@@ -44,7 +44,7 @@ mod sched_linux_like {
         }
     }
 
-    pub type CloneCb<'a> = Box<FnMut() -> isize + 'a>;
+    pub type CloneCb<'a> = Box<dyn FnMut() -> isize + 'a>;
 
     #[repr(C)]
     #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
@@ -113,7 +113,7 @@ mod sched_linux_like {
             let ptr_aligned = ptr.offset((ptr as usize % 16) as isize * -1);
             libc::clone(
                 mem::transmute(
-                    callback as extern "C" fn(*mut Box<::std::ops::FnMut() -> isize>) -> i32,
+                    callback as extern "C" fn(*mut Box<dyn FnMut() -> isize>) -> i32,
                 ),
                 ptr_aligned as *mut c_void,
                 combined,
diff --git a/src/sys/aio.rs b/src/sys/aio.rs
index 40fa4e15..9258a065 100644
--- a/src/sys/aio.rs
+++ b/src/sys/aio.rs
@@ -102,9 +102,9 @@ pub enum Buffer<'a> {
     /// Keeps a reference to a slice
     Phantom(PhantomData<&'a mut [u8]>),
     /// Generic thing that keeps a buffer from dropping
-    BoxedSlice(Box<Borrow<[u8]>>),
+    BoxedSlice(Box<dyn Borrow<[u8]>>),
     /// Generic thing that keeps a mutable buffer from dropping
-    BoxedMutSlice(Box<BorrowMut<[u8]>>),
+    BoxedMutSlice(Box<dyn BorrowMut<[u8]>>),
 }
 
 impl<'a> Debug for Buffer<'a> {
@@ -116,14 +116,14 @@ impl<'a> Debug for Buffer<'a> {
             Buffer::None => write!(fmt, "None"),
             Buffer::Phantom(p) => p.fmt(fmt),
             Buffer::BoxedSlice(ref bs) => {
-                let borrowed : &Borrow<[u8]> = bs.borrow();
+                let borrowed : &dyn Borrow<[u8]> = bs.borrow();
                 write!(fmt, "BoxedSlice({:?})",
-                    borrowed as *const Borrow<[u8]>)
+                    borrowed as *const dyn Borrow<[u8]>)
             },
             Buffer::BoxedMutSlice(ref bms) => {
-                let borrowed : &BorrowMut<[u8]> = bms.borrow();
+                let borrowed : &dyn BorrowMut<[u8]> = bms.borrow();
                 write!(fmt, "BoxedMutSlice({:?})",
-                    borrowed as *const BorrowMut<[u8]>)
+                    borrowed as *const dyn BorrowMut<[u8]>)
             }
         }
     }
@@ -165,7 +165,7 @@ impl<'a> AioCb<'a> {
     ///
     /// It is an error to call this method while the `AioCb` is still in
     /// progress.
-    pub fn boxed_slice(&mut self) -> Option<Box<Borrow<[u8]>>> {
+    pub fn boxed_slice(&mut self) -> Option<Box<dyn Borrow<[u8]>>> {
         assert!(!self.in_progress, "Can't remove the buffer from an AioCb that's still in-progress.  Did you forget to call aio_return?");
         if let Buffer::BoxedSlice(_) = self.buffer {
             let mut oldbuffer = Buffer::None;
@@ -187,7 +187,7 @@ impl<'a> AioCb<'a> {
     ///
     /// It is an error to call this method while the `AioCb` is still in
     /// progress.
-    pub fn boxed_mut_slice(&mut self) -> Option<Box<BorrowMut<[u8]>>> {
+    pub fn boxed_mut_slice(&mut self) -> Option<Box<dyn BorrowMut<[u8]>>> {
         assert!(!self.in_progress, "Can't remove the buffer from an AioCb that's still in-progress.  Did you forget to call aio_return?");
         if let Buffer::BoxedMutSlice(_) = self.buffer {
             let mut oldbuffer = Buffer::None;
@@ -448,12 +448,12 @@ impl<'a> AioCb<'a> {
     /// ```
     ///
     /// [`from_slice`]: #method.from_slice
-    pub fn from_boxed_slice(fd: RawFd, offs: off_t, buf: Box<Borrow<[u8]>>,
+    pub fn from_boxed_slice(fd: RawFd, offs: off_t, buf: Box<dyn Borrow<[u8]>>,
                       prio: libc::c_int, sigev_notify: SigevNotify,
                       opcode: LioOpcode) -> AioCb<'a> {
         let mut a = AioCb::common_init(fd, prio, sigev_notify);
         {
-            let borrowed : &Borrow<[u8]> = buf.borrow();
+            let borrowed : &dyn Borrow<[u8]> = buf.borrow();
             let slice : &[u8] = borrowed.borrow();
             a.aio_nbytes = slice.len() as size_t;
             a.aio_buf = slice.as_ptr() as *mut c_void;
@@ -516,12 +516,12 @@ impl<'a> AioCb<'a> {
     /// [`from_boxed_slice`]: #method.from_boxed_slice
     /// [`from_mut_slice`]: #method.from_mut_slice
     pub fn from_boxed_mut_slice(fd: RawFd, offs: off_t,
-                                mut buf: Box<BorrowMut<[u8]>>,
+                                mut buf: Box<dyn BorrowMut<[u8]>>,
                                 prio: libc::c_int, sigev_notify: SigevNotify,
                                 opcode: LioOpcode) -> AioCb<'a> {
         let mut a = AioCb::common_init(fd, prio, sigev_notify);
         {
-            let borrowed : &mut BorrowMut<[u8]> = buf.borrow_mut();
+            let borrowed : &mut dyn BorrowMut<[u8]> = buf.borrow_mut();
             let slice : &mut [u8] = borrowed.borrow_mut();
             a.aio_nbytes = slice.len() as size_t;
             a.aio_buf = slice.as_mut_ptr() as *mut c_void;
diff --git a/src/sys/socket/mod.rs b/src/sys/socket/mod.rs
index 0e27216f..d651b259 100644
--- a/src/sys/socket/mod.rs
+++ b/src/sys/socket/mod.rs
@@ -893,7 +893,7 @@ pub fn sendmsg(fd: RawFd, iov: &[IoVec<&[u8]>], cmsgs: &[ControlMessage],
 /// # References
 /// [recvmsg(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/recvmsg.html)
 pub fn recvmsg<'a>(fd: RawFd, iov: &[IoVec<&mut [u8]>],
-                   cmsg_buffer: Option<&'a mut CmsgBuffer>,
+                   cmsg_buffer: Option<&'a mut dyn CmsgBuffer>,
                    flags: MsgFlags) -> Result<RecvMsg<'a>>
 {
     let mut address: sockaddr_storage = unsafe { mem::uninitialized() };
diff --git a/test/sys/test_socket.rs b/test/sys/test_socket.rs
index 12afc84c..a71d2767 100644
--- a/test/sys/test_socket.rs
+++ b/test/sys/test_socket.rs
@@ -1,4 +1,5 @@
-use nix::sys::socket::{InetAddr, UnixAddr, getsockname};
+use nix::ifaddrs::InterfaceAddress;
+use nix::sys::socket::{AddressFamily, InetAddr, UnixAddr, getsockname};
 use std::collections::hash_map::DefaultHasher;
 use std::hash::{Hash, Hasher};
 use std::net::{self, Ipv6Addr, SocketAddr, SocketAddrV6};
@@ -302,7 +303,7 @@ pub fn test_af_alg_cipher() {
 #[cfg(any(target_os = "linux", target_os= "android"))]
 #[test]
 pub fn test_af_alg_aead() {
-    use libc;
+    use libc::{ALG_OP_DECRYPT, ALG_OP_ENCRYPT};
     use nix::sys::uio::IoVec;
     use nix::unistd::{read, close};
     use nix::sys::socket::{socket, sendmsg, bind, accept, setsockopt,
@@ -345,7 +346,7 @@ pub fn test_af_alg_aead() {
     let session_socket = accept(sock).expect("accept failed");
 
     let msgs = [
-        ControlMessage::AlgSetOp(&libc::ALG_OP_ENCRYPT),
+        ControlMessage::AlgSetOp(&ALG_OP_ENCRYPT),
         ControlMessage::AlgSetIv(iv.as_slice()),
         ControlMessage::AlgSetAeadAssoclen(&assoc_size)];
     let iov = IoVec::from_slice(&payload);
@@ -368,7 +369,7 @@ pub fn test_af_alg_aead() {
     let session_socket = accept(sock).expect("accept failed");
 
     let msgs = [
-        ControlMessage::AlgSetOp(&libc::ALG_OP_DECRYPT),
+        ControlMessage::AlgSetOp(&ALG_OP_DECRYPT),
         ControlMessage::AlgSetIv(iv.as_slice()),
         ControlMessage::AlgSetAeadAssoclen(&assoc_size),
     ];
@@ -547,11 +548,11 @@ fn test_too_large_cmsgspace() {
 
 #[cfg(any(target_os = "android", target_os = "linux"))]
 fn test_impl_scm_credentials_and_rights(mut space: Vec<u8>) {
-    use libc;
+    use libc::ucred;
     use nix::sys::uio::IoVec;
     use nix::unistd::{pipe, read, write, close, getpid, getuid, getgid};
     use nix::sys::socket::{socketpair, sendmsg, recvmsg, setsockopt,
-                           AddressFamily, SockType, SockFlag,
+                           SockType, SockFlag,
                            ControlMessage, ControlMessageOwned, MsgFlags};
     use nix::sys::socket::sockopt::PassCred;
 
@@ -564,7 +565,7 @@ fn test_impl_scm_credentials_and_rights(mut space: Vec<u8>) {
 
     {
         let iov = [IoVec::from_slice(b"hello")];
-        let cred = libc::ucred {
+        let cred = ucred {
             pid: getpid().as_raw(),
             uid: getuid().as_raw(),
             gid: getgid().as_raw(),
@@ -623,7 +624,7 @@ fn test_impl_scm_credentials_and_rights(mut space: Vec<u8>) {
 // Test creating and using named unix domain sockets
 #[test]
 pub fn test_unixdomain() {
-    use nix::sys::socket::{AddressFamily, SockType, SockFlag};
+    use nix::sys::socket::{SockType, SockFlag};
     use nix::sys::socket::{bind, socket, connect, listen, accept, SockAddr};
     use nix::unistd::{read, write, close};
     use std::thread;
@@ -661,7 +662,7 @@ pub fn test_unixdomain() {
 pub fn test_syscontrol() {
     use nix::Error;
     use nix::errno::Errno;
-    use nix::sys::socket::{AddressFamily, socket, SockAddr, SockType, SockFlag, SockProtocol};
+    use nix::sys::socket::{socket, SockAddr, SockType, SockFlag, SockProtocol};
 
     let fd = socket(AddressFamily::System, SockType::Datagram,
                     SockFlag::empty(), SockProtocol::KextControl)
@@ -673,8 +674,6 @@ pub fn test_syscontrol() {
     // connect(fd, &sockaddr).expect("connect failed");
 }
 
-use nix::ifaddrs::InterfaceAddress;
-use nix::sys::socket::AddressFamily;
 #[cfg(any(
     target_os = "android",
     target_os = "freebsd",
@@ -942,7 +941,7 @@ pub fn test_recv_ipv6pktinfo() {
     use libc;
     use nix::net::if_::*;
     use nix::sys::socket::sockopt::Ipv6RecvPacketInfo;
-    use nix::sys::socket::{bind, AddressFamily, SockFlag, SockType};
+    use nix::sys::socket::{bind, SockFlag, SockType};
     use nix::sys::socket::{getsockname, setsockopt, socket};
     use nix::sys::socket::{recvmsg, sendmsg, ControlMessageOwned, MsgFlags};
     use nix::sys::uio::IoVec;