std: Add `{read,write}_vectored` for more types

This commit implements the `{read,write}_vectored` methods on more types
in the standard library, namely:

* `std::fs::File`
* `std::process::ChildStd{in,out,err}`
* `std::io::Std{in,out,err}`
* `std::io::Std{in,out,err}Lock`
* `std::io::Std{in,out,err}Raw`

Where supported the OS implementations hook up to native support,
otherwise it falls back to the already-defaulted implementation.

3 files changed, 35 insertions, 15 deletions

diff --git a/src/libstd/sys/unix/fs.rs b/src/libstd/sys/unix/fs.rs
index dc3dcb5817c..a14db108c34 100644
--- a/src/libstd/sys/unix/fs.rs
+++ b/src/libstd/sys/unix/fs.rs
@@ -2,7 +2,7 @@ use crate::os::unix::prelude::*;
 
 use crate::ffi::{CString, CStr, OsString, OsStr};
 use crate::fmt;
-use crate::io::{self, Error, ErrorKind, SeekFrom};
+use crate::io::{self, Error, ErrorKind, SeekFrom, IoVec, IoVecMut};
 use crate::mem;
 use crate::path::{Path, PathBuf};
 use crate::ptr;
@@ -560,6 +560,10 @@ impl File {
         self.0.read(buf)
     }
 
+    pub fn read_vectored(&self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+        self.0.read_vectored(bufs)
+    }
+
     pub fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> {
         self.0.read_at(buf, offset)
     }
@@ -568,6 +572,10 @@ impl File {
         self.0.write(buf)
     }
 
+    pub fn write_vectored(&self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+        self.0.write_vectored(bufs)
+    }
+
     pub fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
         self.0.write_at(buf, offset)
     }
diff --git a/src/libstd/sys/unix/pipe.rs b/src/libstd/sys/unix/pipe.rs
index bc3c026adab..a7792d42af9 100644
--- a/src/libstd/sys/unix/pipe.rs
+++ b/src/libstd/sys/unix/pipe.rs
@@ -1,4 +1,4 @@
-use crate::io;
+use crate::io::{self, IoVec, IoVecMut};
 use crate::mem;
 use crate::sync::atomic::{AtomicBool, Ordering};
 use crate::sys::fd::FileDesc;
@@ -60,10 +60,18 @@ impl AnonPipe {
         self.0.read(buf)
     }
 
+    pub fn read_vectored(&self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+        self.0.read_vectored(bufs)
+    }
+
     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
         self.0.write(buf)
     }
 
+    pub fn write_vectored(&self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+        self.0.write_vectored(bufs)
+    }
+
     pub fn fd(&self) -> &FileDesc { &self.0 }
     pub fn into_fd(self) -> FileDesc { self.0 }
 }
diff --git a/src/libstd/sys/unix/stdio.rs b/src/libstd/sys/unix/stdio.rs
index 35f163bbdb1..bc2986f624e 100644
--- a/src/libstd/sys/unix/stdio.rs
+++ b/src/libstd/sys/unix/stdio.rs
@@ -1,5 +1,6 @@
-use crate::io;
+use crate::io::{self, IoVec, IoVecMut};
 use crate::sys::fd::FileDesc;
+use crate::mem::ManuallyDrop;
 
 pub struct Stdin(());
 pub struct Stdout(());
@@ -11,10 +12,11 @@ impl Stdin {
 
 impl io::Read for Stdin {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
-        let fd = FileDesc::new(libc::STDIN_FILENO);
-        let ret = fd.read(buf);
-        fd.into_raw(); // do not close this FD
-        ret
+        ManuallyDrop::new(FileDesc::new(libc::STDIN_FILENO)).read(buf)
+    }
+
+    fn read_vectored(&mut self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+        ManuallyDrop::new(FileDesc::new(libc::STDIN_FILENO)).read_vectored(bufs)
     }
 }
 
@@ -24,10 +26,11 @@ impl Stdout {
 
 impl io::Write for Stdout {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        let fd = FileDesc::new(libc::STDOUT_FILENO);
-        let ret = fd.write(buf);
-        fd.into_raw(); // do not close this FD
-        ret
+        ManuallyDrop::new(FileDesc::new(libc::STDOUT_FILENO)).write(buf)
+    }
+
+    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+        ManuallyDrop::new(FileDesc::new(libc::STDOUT_FILENO)).write_vectored(bufs)
     }
 
     fn flush(&mut self) -> io::Result<()> {
@@ -41,10 +44,11 @@ impl Stderr {
 
 impl io::Write for Stderr {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        let fd = FileDesc::new(libc::STDERR_FILENO);
-        let ret = fd.write(buf);
-        fd.into_raw(); // do not close this FD
-        ret
+        ManuallyDrop::new(FileDesc::new(libc::STDERR_FILENO)).write(buf)
+    }
+
+    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+        ManuallyDrop::new(FileDesc::new(libc::STDERR_FILENO)).write_vectored(bufs)
     }
 
     fn flush(&mut self) -> io::Result<()> {