1 files changed, 42 insertions, 13 deletions

diff --git a/library/std/src/fs.rs b/library/std/src/fs.rs
index 1293abddaf3..77e94365b08 100644
--- a/library/std/src/fs.rs
+++ b/library/std/src/fs.rs
@@ -214,7 +214,7 @@ pub struct Permissions(fs_imp::FilePermissions);
 /// A structure representing a type of file with accessors for each file type.
 /// It is returned by [`Metadata::file_type`] method.
 #[stable(feature = "file_type", since = "1.1.0")]
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
 #[cfg_attr(not(test), rustc_diagnostic_item = "FileType")]
 pub struct FileType(fs_imp::FileType);
 
@@ -408,6 +408,9 @@ impl File {
     ///
     /// This function will create a file if it does not exist, or return an error if it does. This
     /// way, if the call succeeds, the file returned is guaranteed to be new.
+    /// If a file exists at the target location, creating a new file will fail with [`AlreadyExists`]
+    /// or another error based on the situation. See [`OpenOptions::open`] for a
+    /// non-exhaustive list of likely errors.
     ///
     /// This option is useful because it is atomic. Otherwise between checking whether a file
     /// exists and creating a new one, the file may have been created by another process (a TOCTOU
@@ -416,6 +419,8 @@ impl File {
     /// This can also be written using
     /// `File::options().read(true).write(true).create_new(true).open(...)`.
     ///
+    /// [`AlreadyExists`]: crate::io::ErrorKind::AlreadyExists
+    ///
     /// # Examples
     ///
     /// ```no_run
@@ -1071,6 +1076,9 @@ impl OpenOptions {
     ///
     /// No file is allowed to exist at the target location, also no (dangling) symlink. In this
     /// way, if the call succeeds, the file returned is guaranteed to be new.
+    /// If a file exists at the target location, creating a new file will fail with [`AlreadyExists`]
+    /// or another error based on the situation. See [`OpenOptions::open`] for a
+    /// non-exhaustive list of likely errors.
     ///
     /// This option is useful because it is atomic. Otherwise between checking
     /// whether a file exists and creating a new one, the file may have been
@@ -1084,6 +1092,7 @@ impl OpenOptions {
     ///
     /// [`.create()`]: OpenOptions::create
     /// [`.truncate()`]: OpenOptions::truncate
+    /// [`AlreadyExists`]: io::ErrorKind::AlreadyExists
     ///
     /// # Examples
     ///
@@ -1410,15 +1419,20 @@ impl Metadata {
 #[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Metadata {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("Metadata")
-            .field("file_type", &self.file_type())
-            .field("is_dir", &self.is_dir())
-            .field("is_file", &self.is_file())
-            .field("permissions", &self.permissions())
-            .field("modified", &self.modified())
-            .field("accessed", &self.accessed())
-            .field("created", &self.created())
-            .finish_non_exhaustive()
+        let mut debug = f.debug_struct("Metadata");
+        debug.field("file_type", &self.file_type());
+        debug.field("permissions", &self.permissions());
+        debug.field("len", &self.len());
+        if let Ok(modified) = self.modified() {
+            debug.field("modified", &modified);
+        }
+        if let Ok(accessed) = self.accessed() {
+            debug.field("accessed", &accessed);
+        }
+        if let Ok(created) = self.created() {
+            debug.field("created", &created);
+        }
+        debug.finish_non_exhaustive()
     }
 }
 
@@ -1684,6 +1698,17 @@ impl FileType {
     }
 }
 
+#[stable(feature = "std_debug", since = "1.16.0")]
+impl fmt::Debug for FileType {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("FileType")
+            .field("is_file", &self.is_file())
+            .field("is_dir", &self.is_dir())
+            .field("is_symlink", &self.is_symlink())
+            .finish_non_exhaustive()
+    }
+}
+
 impl AsInner<fs_imp::FileType> for FileType {
     #[inline]
     fn as_inner(&self) -> &fs_imp::FileType {
@@ -2242,7 +2267,7 @@ pub fn canonicalize<P: AsRef<Path>>(path: P) -> io::Result<PathBuf> {
 /// # Platform-specific behavior
 ///
 /// This function currently corresponds to the `mkdir` function on Unix
-/// and the `CreateDirectory` function on Windows.
+/// and the `CreateDirectoryW` function on Windows.
 /// Note that, this [may change in the future][changes].
 ///
 /// [changes]: io#platform-specific-behavior
@@ -2282,10 +2307,14 @@ pub fn create_dir<P: AsRef<Path>>(path: P) -> io::Result<()> {
 /// Recursively create a directory and all of its parent components if they
 /// are missing.
 ///
+/// If this function returns an error, some of the parent components might have
+/// been created already.
+///
 /// # Platform-specific behavior
 ///
-/// This function currently corresponds to the `mkdir` function on Unix
-/// and the `CreateDirectory` function on Windows.
+/// This function currently corresponds to multiple calls to the `mkdir`
+/// function on Unix and the `CreateDirectoryW` function on Windows.
+///
 /// Note that, this [may change in the future][changes].
 ///
 /// [changes]: io#platform-specific-behavior