diff options
Diffstat (limited to 'src/libstd/fs.rs')
| -rw-r--r-- | src/libstd/fs.rs | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/src/libstd/fs.rs b/src/libstd/fs.rs index 5cea389531f..292a78278ab 100644 --- a/src/libstd/fs.rs +++ b/src/libstd/fs.rs @@ -81,9 +81,18 @@ use time::SystemTime; /// # } /// ``` /// +/// Note that, although read and write methods require a `&mut File`, because +/// of the interfaces for [`Read`] and [`Write`], the holder of a `&File` can +/// still modify the file, either through methods that take `&File` or by +/// retrieving the underlying OS object and modifying the file that way. +/// Additionally, many operating systems allow concurrent modification of files +/// by different processes. Avoid assuming that holding a `&File` means that the +/// file will not change. +/// /// [`Seek`]: ../io/trait.Seek.html /// [`String`]: ../string/struct.String.html /// [`Read`]: ../io/trait.Read.html +/// [`Write`]: ../io/trait.Write.html /// [`BufReader<R>`]: ../io/struct.BufReader.html #[stable(feature = "rust1", since = "1.0.0")] pub struct File { @@ -459,6 +468,9 @@ impl File { /// # Ok(()) /// # } /// ``` + /// + /// Note that this method alters the content of the underlying file, even + /// though it takes `&self` rather than `&mut self`. #[stable(feature = "rust1", since = "1.0.0")] pub fn set_len(&self, size: u64) -> io::Result<()> { self.inner.truncate(size) @@ -557,6 +569,9 @@ impl File { /// # Ok(()) /// # } /// ``` + /// + /// Note that this method alters the permissions of the underlying file, + /// even though it takes `&self` rather than `&mut self`. #[stable(feature = "set_permissions_atomic", since = "1.16.0")] pub fn set_permissions(&self, perm: Permissions) -> io::Result<()> { self.inner.set_permissions(perm.0) |