Update top-level path doc examples to show results.

src/libstd/path.rs

@@ -25,11 +25,18 @@
 //!
 //! ```rust
 //! use std::path::Path;
+//! use std::ffi::OsStr;
 //!
 //! let path = Path::new("/tmp/foo/bar.txt");
-//! let file = path.file_name();
+//!
+//! let parent = path.parent();
+//! assert_eq!(parent, Some(Path::new("/tmp/foo")));
+//!
+//! let file_stem = path.file_stem();
+//! assert_eq!(file_stem, Some(OsStr::new("bar")));
+//!
 //! let extension = path.extension();
-//! let parent_dir = path.parent();
+//! assert_eq!(extension, Some(OsStr::new("txt")));
 //! ```
 //!
 //! To build or modify paths, use `PathBuf`:
@@ -1319,13 +1326,19 @@ impl AsRef<OsStr> for PathBuf {
 ///
 /// ```
 /// use std::path::Path;
+/// use std::ffi::OsStr;
 ///
 /// let path = Path::new("/tmp/foo/bar.txt");
-/// let file = path.file_name();
-/// let extension = path.extension();
-/// let parent_dir = path.parent();
-/// ```
 ///
+/// let parent = path.parent();
+/// assert_eq!(parent, Some(Path::new("/tmp/foo")));
+///
+/// let file_stem = path.file_stem();
+/// assert_eq!(file_stem, Some(OsStr::new("bar")));
+///
+/// let extension = path.extension();
+/// assert_eq!(extension, Some(OsStr::new("txt")));
+/// ```
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Path {
     inner: OsStr,