Implement IO traits for Arc

library/std/src/fs.rs

@@ -45,7 +45,6 @@ use crate::ffi::OsString;
 use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut, Read, Seek, SeekFrom, Write};
 use crate::path::{Path, PathBuf};
 use crate::sealed::Sealed;
-use crate::sync::Arc;
 use crate::sys::{AsInner, AsInnerMut, FromInner, IntoInner, fs as fs_imp};
 use crate::time::SystemTime;
 use crate::{error, fmt};
@@ -1542,58 +1541,6 @@ impl Seek for File {
     }
 }
 
-#[stable(feature = "io_traits_arc", since = "1.73.0")]
-impl Read for Arc<File> {
-    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
-        (&**self).read(buf)
-    }
-    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
-        (&**self).read_vectored(bufs)
-    }
-    fn read_buf(&mut self, cursor: BorrowedCursor<'_>) -> io::Result<()> {
-        (&**self).read_buf(cursor)
-    }
-    #[inline]
-    fn is_read_vectored(&self) -> bool {
-        (&**self).is_read_vectored()
-    }
-    fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
-        (&**self).read_to_end(buf)
-    }
-    fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
-        (&**self).read_to_string(buf)
-    }
-}
-#[stable(feature = "io_traits_arc", since = "1.73.0")]
-impl Write for Arc<File> {
-    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        (&**self).write(buf)
-    }
-    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
-        (&**self).write_vectored(bufs)
-    }
-    #[inline]
-    fn is_write_vectored(&self) -> bool {
-        (&**self).is_write_vectored()
-    }
-    #[inline]
-    fn flush(&mut self) -> io::Result<()> {
-        (&**self).flush()
-    }
-}
-#[stable(feature = "io_traits_arc", since = "1.73.0")]
-impl Seek for Arc<File> {
-    fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
-        (&**self).seek(pos)
-    }
-    fn stream_len(&mut self) -> io::Result<u64> {
-        (&**self).stream_len()
-    }
-    fn stream_position(&mut self) -> io::Result<u64> {
-        (&**self).stream_position()
-    }
-}
-
 impl Dir {
     /// Attempts to open a directory at `path` in read-only mode.
     ///

library/std/src/io/impls.rs

@@ -4,6 +4,7 @@ mod tests;
 use crate::alloc::Allocator;
 use crate::collections::VecDeque;
 use crate::io::{self, BorrowedCursor, BufRead, IoSlice, IoSliceMut, Read, Seek, SeekFrom, Write};
+use crate::sync::Arc;
 use crate::{cmp, fmt, mem, str};
 
 // =============================================================================
@@ -286,6 +287,72 @@ impl<B: BufRead + ?Sized> BufRead for Box<B> {
         (**self).read_line(buf)
     }
 }
+#[stable(feature = "arc_io_traits", since = "CURRENT_RUSTC_VERSION")]
+#[cfg(all(not(no_rc), not(no_sync), target_has_atomic = "ptr"))]
+impl<R> Read for Arc<R>
+where
+    R: Read,
+    for<'a> &'a R: Read,
+{
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        (&**self).read(buf)
+    }
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
+        (&**self).read_vectored(bufs)
+    }
+    fn read_buf(&mut self, cursor: BorrowedCursor<'_>) -> io::Result<()> {
+        (&**self).read_buf(cursor)
+    }
+    #[inline]
+    fn is_read_vectored(&self) -> bool {
+        (&**self).is_read_vectored()
+    }
+    fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
+        (&**self).read_to_end(buf)
+    }
+    fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
+        (&**self).read_to_string(buf)
+    }
+}
+#[stable(feature = "arc_io_traits", since = "CURRENT_RUSTC_VERSION")]
+#[cfg(all(not(no_rc), not(no_sync), target_has_atomic = "ptr"))]
+impl<W> Write for Arc<W>
+where
+    W: Write,
+    for<'a> &'a W: Write,
+{
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        (&**self).write(buf)
+    }
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        (&**self).write_vectored(bufs)
+    }
+    #[inline]
+    fn is_write_vectored(&self) -> bool {
+        (&**self).is_write_vectored()
+    }
+    #[inline]
+    fn flush(&mut self) -> io::Result<()> {
+        (&**self).flush()
+    }
+}
+#[stable(feature = "arc_io_traits", since = "CURRENT_RUSTC_VERSION")]
+#[cfg(all(not(no_rc), not(no_sync), target_has_atomic = "ptr"))]
+impl<S> Seek for Arc<S>
+where
+    S: Seek,
+    for<'a> &'a S: Seek,
+{
+    fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
+        (&**self).seek(pos)
+    }
+    fn stream_len(&mut self) -> io::Result<u64> {
+        (&**self).stream_len()
+    }
+    fn stream_position(&mut self) -> io::Result<u64> {
+        (&**self).stream_position()
+    }
+}
 
 // =============================================================================
 // In-memory buffer implementations