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, 31 insertions, 3 deletions

diff --git a/src/libstd/sys/windows/fs.rs b/src/libstd/sys/windows/fs.rs
index 4ebbb0707f7..1d8e47a4793 100644
--- a/src/libstd/sys/windows/fs.rs
+++ b/src/libstd/sys/windows/fs.rs
@@ -2,7 +2,7 @@ use crate::os::windows::prelude::*;
 
 use crate::ffi::OsString;
 use crate::fmt;
-use crate::io::{self, Error, SeekFrom};
+use crate::io::{self, Error, SeekFrom, IoVec, IoVecMut};
 use crate::mem;
 use crate::path::{Path, PathBuf};
 use crate::ptr;
@@ -314,6 +314,10 @@ impl File {
         self.handle.read(buf)
     }
 
+    pub fn read_vectored(&self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+        self.handle.read_vectored(bufs)
+    }
+
     pub fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> {
         self.handle.read_at(buf, offset)
     }
@@ -322,6 +326,10 @@ impl File {
         self.handle.write(buf)
     }
 
+    pub fn write_vectored(&self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+        self.handle.write_vectored(bufs)
+    }
+
     pub fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
         self.handle.write_at(buf, offset)
     }
diff --git a/src/libstd/sys/windows/handle.rs b/src/libstd/sys/windows/handle.rs
index 02549088c87..c3fa6c4e0bd 100644
--- a/src/libstd/sys/windows/handle.rs
+++ b/src/libstd/sys/windows/handle.rs
@@ -1,7 +1,7 @@
 #![unstable(issue = "0", feature = "windows_handle")]
 
 use crate::cmp;
-use crate::io::{self, ErrorKind, Read};
+use crate::io::{self, ErrorKind, Read, IoVec, IoVecMut};
 use crate::mem;
 use crate::ops::Deref;
 use crate::ptr;
@@ -89,6 +89,10 @@ impl RawHandle {
         }
     }
 
+    pub fn read_vectored(&self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+        crate::io::default_read_vectored(|buf| self.read(buf), bufs)
+    }
+
     pub fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> {
         let mut read = 0;
         let len = cmp::min(buf.len(), <c::DWORD>::max_value() as usize) as c::DWORD;
@@ -169,6 +173,10 @@ impl RawHandle {
         Ok(amt as usize)
     }
 
+    pub fn write_vectored(&self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+        crate::io::default_write_vectored(|buf| self.write(buf), bufs)
+    }
+
     pub fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
         let mut written = 0;
         let len = cmp::min(buf.len(), <c::DWORD>::max_value() as usize) as c::DWORD;
@@ -199,4 +207,8 @@ impl<'a> Read for &'a RawHandle {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
         (**self).read(buf)
     }
+
+    fn read_vectored(&mut self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+        (**self).read_vectored(bufs)
+    }
 }
diff --git a/src/libstd/sys/windows/pipe.rs b/src/libstd/sys/windows/pipe.rs
index b38727830f3..6613d3a0567 100644
--- a/src/libstd/sys/windows/pipe.rs
+++ b/src/libstd/sys/windows/pipe.rs
@@ -1,7 +1,7 @@
 use crate::os::windows::prelude::*;
 
 use crate::ffi::OsStr;
-use crate::io;
+use crate::io::{self, IoVec, IoVecMut};
 use crate::mem;
 use crate::path::Path;
 use crate::ptr;
@@ -166,9 +166,17 @@ impl AnonPipe {
         self.inner.read(buf)
     }
 
+    pub fn read_vectored(&self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+        self.inner.read_vectored(bufs)
+    }
+
     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
         self.inner.write(buf)
     }
+
+    pub fn write_vectored(&self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+        self.inner.write_vectored(bufs)
+    }
 }
 
 pub fn read2(p1: AnonPipe,