Auto merge of #101115 - matthiaskrgr:rollup-iy14ztr, r=matthiaskrgr

Rollup of 13 pull requests

Successful merges:

 - #97015 (std::io: migrate ReadBuf to BorrowBuf/BorrowCursor)
 - #98301 (Add GDB/LLDB pretty-printers for NonZero types)
 - #99570 (Box::from(slice): Clarify that contents are copied)
 - #100296 (Add standard C error function aliases to last_os_error)
 - #100520 (Add mention of `BufReader` in `Read::bytes` docs)
 - #100885 (Export Cancel from std::os::fortanix_sgx::usercalls::raw)
 - #100955 (Some papercuts on error::Error)
 - #101002 (Provide structured suggestion for `hashmap[idx] = val`)
 - #101038 (no alignment check during interning)
 - #101055 (Use smaller span for suggestions)
 - #101091 (Extend attrs if local_def_id exists)
 - #101098 (rustc_middle: Remove `Visibility::Invisible`)
 - #101102 (unstable-book-gen: use std::fs::write)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

2 files changed, 8 insertions, 9 deletions

diff --git a/library/std/src/sys/unix/fd.rs b/library/std/src/sys/unix/fd.rs
index 30812dabb4e..dbaa3c33e2e 100644
--- a/library/std/src/sys/unix/fd.rs
+++ b/library/std/src/sys/unix/fd.rs
@@ -4,7 +4,7 @@
 mod tests;
 
 use crate::cmp;
-use crate::io::{self, IoSlice, IoSliceMut, Read, ReadBuf};
+use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut, Read};
 use crate::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
 use crate::sys::cvt;
 use crate::sys_common::{AsInner, FromInner, IntoInner};
@@ -131,20 +131,19 @@ impl FileDesc {
         }
     }
 
-    pub fn read_buf(&self, buf: &mut ReadBuf<'_>) -> io::Result<()> {
+    pub fn read_buf(&self, mut cursor: BorrowedCursor<'_>) -> io::Result<()> {
         let ret = cvt(unsafe {
             libc::read(
                 self.as_raw_fd(),
-                buf.unfilled_mut().as_mut_ptr() as *mut libc::c_void,
-                cmp::min(buf.remaining(), READ_LIMIT),
+                cursor.as_mut().as_mut_ptr() as *mut libc::c_void,
+                cmp::min(cursor.capacity(), READ_LIMIT),
             )
         })?;
 
         // Safety: `ret` bytes were written to the initialized portion of the buffer
         unsafe {
-            buf.assume_init(ret as usize);
+            cursor.advance(ret as usize);
         }
-        buf.add_filled(ret as usize);
         Ok(())
     }
 
diff --git a/library/std/src/sys/unix/fs.rs b/library/std/src/sys/unix/fs.rs
index f38d2fd3d70..cc347e3586a 100644
--- a/library/std/src/sys/unix/fs.rs
+++ b/library/std/src/sys/unix/fs.rs
@@ -2,7 +2,7 @@ use crate::os::unix::prelude::*;
 
 use crate::ffi::{CStr, CString, OsStr, OsString};
 use crate::fmt;
-use crate::io::{self, Error, IoSlice, IoSliceMut, ReadBuf, SeekFrom};
+use crate::io::{self, BorrowedCursor, Error, IoSlice, IoSliceMut, SeekFrom};
 use crate::mem;
 use crate::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd};
 use crate::path::{Path, PathBuf};
@@ -1037,8 +1037,8 @@ impl File {
         self.0.read_at(buf, offset)
     }
 
-    pub fn read_buf(&self, buf: &mut ReadBuf<'_>) -> io::Result<()> {
-        self.0.read_buf(buf)
+    pub fn read_buf(&self, cursor: BorrowedCursor<'_>) -> io::Result<()> {
+        self.0.read_buf(cursor)
     }
 
     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {