Add doc example for `CStr::to_str`.

diff --git a/src/libstd/ffi/c_str.rs b/src/libstd/ffi/c_str.rs
index 0ad4c74536a8b220814069673e2e3d0aa9ea7c75..8a7757fde882b76c38ad847f2e8ba6e4c2d2e4f0 100644 (file)
--- a/src/libstd/ffi/c_str.rs
+++ b/src/libstd/ffi/c_str.rs
@@ -894,6 +894,15 @@ pub fn to_bytes_with_nul(&self) -> &[u8] {
     /// > check whenever this method is called.
     ///
     /// [`&str`]: ../primitive.str.html
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::ffi::CStr;
+    ///
+    /// let c_str = CStr::from_bytes_with_nul(b"foo\0").unwrap();
+    /// assert_eq!(c_str.to_str(), Ok("foo"));
+    /// ```
     #[stable(feature = "cstr_to_str", since = "1.4.0")]
     pub fn to_str(&self) -> Result<&str, str::Utf8Error> {
         // NB: When CStr is changed to perform the length check in .to_bytes()