Stabilized vectored IO

This renames `std::io::IoVec` to `std::io::IoSlice` and
`std::io::IoVecMut` to `std::io::IoSliceMut`, and stabilizes
`std::io::IoSlice`, `std::io::IoSliceMut`,
`std::io::Read::read_vectored`, and `std::io::Write::write_vectored`.

Closes #58452

src/libstd/io/stdio.rs

@@ -5,7 +5,7 @@ use crate::io::prelude::*;
 use crate::cell::RefCell;
 use crate::fmt;
 use crate::io::lazy::Lazy;
-use crate::io::{self, Initializer, BufReader, LineWriter, IoVec, IoVecMut};
+use crate::io::{self, Initializer, BufReader, LineWriter, IoSlice, IoSliceMut};
 use crate::sync::{Arc, Mutex, MutexGuard};
 use crate::sys::stdio;
 use crate::sys_common::remutex::{ReentrantMutex, ReentrantMutexGuard};
@@ -75,7 +75,7 @@ fn stderr_raw() -> io::Result<StderrRaw> { stdio::Stderr::new().map(StderrRaw) }
 impl Read for StdinRaw {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { self.0.read(buf) }
 
-    fn read_vectored(&mut self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         self.0.read_vectored(bufs)
     }
 
@@ -87,7 +87,7 @@ impl Read for StdinRaw {
 impl Write for StdoutRaw {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> { self.0.write(buf) }
 
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         self.0.write_vectored(bufs)
     }
 
@@ -96,7 +96,7 @@ impl Write for StdoutRaw {
 impl Write for StderrRaw {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> { self.0.write(buf) }
 
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         self.0.write_vectored(bufs)
     }
 
@@ -116,7 +116,7 @@ impl<W: io::Write> io::Write for Maybe<W> {
         }
     }
 
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         let total = bufs.iter().map(|b| b.len()).sum();
         match self {
             Maybe::Real(w) => handle_ebadf(w.write_vectored(bufs), total),
@@ -140,7 +140,7 @@ impl<R: io::Read> io::Read for Maybe<R> {
         }
     }
 
-    fn read_vectored(&mut self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         match self {
             Maybe::Real(r) => handle_ebadf(r.read_vectored(bufs), 0),
             Maybe::Fake => Ok(0)
@@ -334,7 +334,7 @@ impl Read for Stdin {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
         self.lock().read(buf)
     }
-    fn read_vectored(&mut self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         self.lock().read_vectored(bufs)
     }
     #[inline]
@@ -358,7 +358,7 @@ impl Read for StdinLock<'_> {
         self.inner.read(buf)
     }
 
-    fn read_vectored(&mut self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         self.inner.read_vectored(bufs)
     }
 
@@ -520,7 +520,7 @@ impl Write for Stdout {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
         self.lock().write(buf)
     }
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         self.lock().write_vectored(bufs)
     }
     fn flush(&mut self) -> io::Result<()> {
@@ -538,7 +538,7 @@ impl Write for StdoutLock<'_> {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
         self.inner.borrow_mut().write(buf)
     }
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         self.inner.borrow_mut().write_vectored(bufs)
     }
     fn flush(&mut self) -> io::Result<()> {
@@ -679,7 +679,7 @@ impl Write for Stderr {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
         self.lock().write(buf)
     }
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         self.lock().write_vectored(bufs)
     }
     fn flush(&mut self) -> io::Result<()> {
@@ -697,7 +697,7 @@ impl Write for StderrLock<'_> {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
         self.inner.borrow_mut().write(buf)
     }
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         self.inner.borrow_mut().write_vectored(bufs)
     }
     fn flush(&mut self) -> io::Result<()> {