impl Debug for ReadDir

It is good practice to implement Debug for public types, and
indicating what directory you're reading seems useful.

Signed-off-by: David Henningsson <diwic@ubuntu.com>

2 files changed, 16 insertions, 0 deletions

diff --git a/src/libstd/sys/unix/fs.rs b/src/libstd/sys/unix/fs.rs
index fe8cbc84215..b77008676b1 100644
--- a/src/libstd/sys/unix/fs.rs
+++ b/src/libstd/sys/unix/fs.rs
@@ -193,6 +193,14 @@ impl FromInner<u32> for FilePermissions {
     }
 }
 
+impl fmt::Debug for ReadDir {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        // This will only be called from std::fs::ReadDir, which will add a "ReadDir()" frame.
+        // Thus the result will be e g 'ReadDir("/home")'
+        fmt::Debug::fmt(&*self.root, f)
+    }
+}
+
 impl Iterator for ReadDir {
     type Item = io::Result<DirEntry>;
 
diff --git a/src/libstd/sys/windows/fs.rs b/src/libstd/sys/windows/fs.rs
index a927eae020d..98fd15f863b 100644
--- a/src/libstd/sys/windows/fs.rs
+++ b/src/libstd/sys/windows/fs.rs
@@ -81,6 +81,14 @@ pub struct FilePermissions { attrs: c::DWORD }
 
 pub struct DirBuilder;
 
+impl fmt::Debug for ReadDir {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        // This will only be called from std::fs::ReadDir, which will add a "ReadDir()" frame.
+        // Thus the result will be e g 'ReadDir("C:\")'
+        fmt::Debug::fmt(&*self.root, f)
+    }
+}
+
 impl Iterator for ReadDir {
     type Item = io::Result<DirEntry>;
     fn next(&mut self) -> Option<io::Result<DirEntry>> {