Document various I/O handle conversions

library/std/src/os/fd/owned.rs

@@ -288,6 +288,7 @@ fn as_fd(&self) -> BorrowedFd<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<fs::File> for OwnedFd {
+    /// Takes ownership of a [`File`](fs::File)'s underlying file descriptor.
     #[inline]
     fn from(file: fs::File) -> OwnedFd {
         file.into_inner().into_inner().into_inner()
@@ -296,6 +297,8 @@ fn from(file: fs::File) -> OwnedFd {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<OwnedFd> for fs::File {
+    /// Returns a [`File`](fs::File) that takes ownership of the given
+    /// file descriptor.
     #[inline]
     fn from(owned_fd: OwnedFd) -> Self {
         Self::from_inner(FromInner::from_inner(FromInner::from_inner(owned_fd)))
@@ -312,6 +315,7 @@ fn as_fd(&self) -> BorrowedFd<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<crate::net::TcpStream> for OwnedFd {
+    /// Takes ownership of a [`TcpStream`](crate::net::TcpStream)'s socket file descriptor.
     #[inline]
     fn from(tcp_stream: crate::net::TcpStream) -> OwnedFd {
         tcp_stream.into_inner().into_socket().into_inner().into_inner().into()
@@ -338,6 +342,7 @@ fn as_fd(&self) -> BorrowedFd<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<crate::net::TcpListener> for OwnedFd {
+    /// Takes ownership of a [`TcpListener`](crate::net::TcpListener)'s socket file descriptor.
     #[inline]
     fn from(tcp_listener: crate::net::TcpListener) -> OwnedFd {
         tcp_listener.into_inner().into_socket().into_inner().into_inner().into()
@@ -364,6 +369,7 @@ fn as_fd(&self) -> BorrowedFd<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<crate::net::UdpSocket> for OwnedFd {
+    /// Takes ownership of a [`UdpSocket`](crate::net::UdpSocket)'s file descriptor.
     #[inline]
     fn from(udp_socket: crate::net::UdpSocket) -> OwnedFd {
         udp_socket.into_inner().into_socket().into_inner().into_inner().into()

library/std/src/os/unix/net/datagram.rs

@@ -1024,6 +1024,7 @@ fn as_fd(&self) -> BorrowedFd<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<UnixDatagram> for OwnedFd {
+    /// Takes ownership of a [`UnixDatagram`]'s socket file descriptor.
     #[inline]
     fn from(unix_datagram: UnixDatagram) -> OwnedFd {
         unsafe { OwnedFd::from_raw_fd(unix_datagram.into_raw_fd()) }

library/std/src/os/unix/net/listener.rs

@@ -346,6 +346,7 @@ fn from(fd: OwnedFd) -> UnixListener {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<UnixListener> for OwnedFd {
+    /// Takes ownership of a [`UnixListener`]'s socket file descriptor.
     #[inline]
     fn from(listener: UnixListener) -> OwnedFd {
         listener.0.into_inner().into_inner()

library/std/src/os/unix/net/stream.rs

@@ -752,6 +752,7 @@ fn as_fd(&self) -> BorrowedFd<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<UnixStream> for OwnedFd {
+    /// Takes ownership of a [`UnixStream`]'s socket file descriptor.
     #[inline]
     fn from(unix_stream: UnixStream) -> OwnedFd {
         unsafe { OwnedFd::from_raw_fd(unix_stream.into_raw_fd()) }

library/std/src/os/unix/process.rs

@@ -362,6 +362,8 @@ unsafe fn from_raw_fd(fd: RawFd) -> process::Stdio {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<OwnedFd> for process::Stdio {
+    /// Takes ownership of a file descriptor and returns a [`Stdio`](process::Stdio)
+    /// that can attach a stream to it.
     #[inline]
     fn from(fd: OwnedFd) -> process::Stdio {
         let fd = sys::fd::FileDesc::from_inner(fd);
@@ -428,6 +430,7 @@ fn as_fd(&self) -> BorrowedFd<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<crate::process::ChildStdin> for OwnedFd {
+    /// Takes ownership of a [`ChildStdin`](crate::process::ChildStdin)'s file descriptor.
     #[inline]
     fn from(child_stdin: crate::process::ChildStdin) -> OwnedFd {
         child_stdin.into_inner().into_inner().into_inner()
@@ -458,6 +461,7 @@ fn as_fd(&self) -> BorrowedFd<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<crate::process::ChildStdout> for OwnedFd {
+    /// Takes ownership of a [`ChildStdout`](crate::process::ChildStdout)'s file descriptor.
     #[inline]
     fn from(child_stdout: crate::process::ChildStdout) -> OwnedFd {
         child_stdout.into_inner().into_inner().into_inner()
@@ -488,6 +492,7 @@ fn as_fd(&self) -> BorrowedFd<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<crate::process::ChildStderr> for OwnedFd {
+    /// Takes ownership of a [`ChildStderr`](crate::process::ChildStderr)'s file descriptor.
     #[inline]
     fn from(child_stderr: crate::process::ChildStderr) -> OwnedFd {
         child_stderr.into_inner().into_inner().into_inner()

library/std/src/os/windows/io/handle.rs

@@ -502,6 +502,7 @@ fn as_handle(&self) -> BorrowedHandle<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<fs::File> for OwnedHandle {
+    /// Takes ownership of a [`File`](fs::File)'s underlying file handle.
     #[inline]
     fn from(file: fs::File) -> OwnedHandle {
         file.into_inner().into_inner().into_inner()
@@ -510,6 +511,7 @@ fn from(file: fs::File) -> OwnedHandle {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<OwnedHandle> for fs::File {
+    /// Returns a [`File`](fs::File) that takes ownership of the given handle.
     #[inline]
     fn from(owned: OwnedHandle) -> Self {
         Self::from_inner(FromInner::from_inner(FromInner::from_inner(owned)))
@@ -574,6 +576,7 @@ fn as_handle(&self) -> BorrowedHandle<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<crate::process::ChildStdin> for OwnedHandle {
+    /// Takes ownership of a [`ChildStdin`](crate::process::ChildStdin)'s file handle.
     #[inline]
     fn from(child_stdin: crate::process::ChildStdin) -> OwnedHandle {
         unsafe { OwnedHandle::from_raw_handle(child_stdin.into_raw_handle()) }
@@ -590,6 +593,7 @@ fn as_handle(&self) -> BorrowedHandle<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<crate::process::ChildStdout> for OwnedHandle {
+    /// Takes ownership of a [`ChildStdout`](crate::process::ChildStdout)'s file handle.
     #[inline]
     fn from(child_stdout: crate::process::ChildStdout) -> OwnedHandle {
         unsafe { OwnedHandle::from_raw_handle(child_stdout.into_raw_handle()) }
@@ -606,6 +610,7 @@ fn as_handle(&self) -> BorrowedHandle<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<crate::process::ChildStderr> for OwnedHandle {
+    /// Takes ownership of a [`ChildStderr`](crate::process::ChildStderr)'s file handle.
     #[inline]
     fn from(child_stderr: crate::process::ChildStderr) -> OwnedHandle {
         unsafe { OwnedHandle::from_raw_handle(child_stderr.into_raw_handle()) }

library/std/src/os/windows/io/socket.rs

@@ -319,6 +319,7 @@ fn as_socket(&self) -> BorrowedSocket<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<crate::net::TcpStream> for OwnedSocket {
+    /// Takes ownership of a [`TcpStream`](crate::net::TcpStream)'s socket.
     #[inline]
     fn from(tcp_stream: crate::net::TcpStream) -> OwnedSocket {
         unsafe { OwnedSocket::from_raw_socket(tcp_stream.into_raw_socket()) }
@@ -343,6 +344,7 @@ fn as_socket(&self) -> BorrowedSocket<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<crate::net::TcpListener> for OwnedSocket {
+    /// Takes ownership of a [`TcpListener`](crate::net::TcpListener)'s socket.
     #[inline]
     fn from(tcp_listener: crate::net::TcpListener) -> OwnedSocket {
         unsafe { OwnedSocket::from_raw_socket(tcp_listener.into_raw_socket()) }
@@ -367,6 +369,7 @@ fn as_socket(&self) -> BorrowedSocket<'_> {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<crate::net::UdpSocket> for OwnedSocket {
+    /// Takes ownership of a [`UdpSocket`](crate::net::UdpSocket)'s underlying socket.
     #[inline]
     fn from(udp_socket: crate::net::UdpSocket) -> OwnedSocket {
         unsafe { OwnedSocket::from_raw_socket(udp_socket.into_raw_socket()) }

library/std/src/os/windows/process.rs

@@ -24,6 +24,8 @@ unsafe fn from_raw_handle(handle: RawHandle) -> process::Stdio {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<OwnedHandle> for process::Stdio {
+    /// Takes ownership of a handle and returns a [`Stdio`](process::Stdio)
+    /// that can attach a stream to it.
     fn from(handle: OwnedHandle) -> process::Stdio {
         let handle = sys::handle::Handle::from_inner(handle);
         let io = sys::process::Stdio::Handle(handle);
@@ -56,6 +58,7 @@ fn into_raw_handle(self) -> RawHandle {
 
 #[stable(feature = "io_safety", since = "1.63.0")]
 impl From<process::Child> for OwnedHandle {
+    /// Takes ownership of a [`Child`](process::Child)'s process handle.
     fn from(child: process::Child) -> OwnedHandle {
         child.into_inner().into_handle().into_inner()
     }