Rollup merge of #102283 - GuillaumeGomez:option-code-example-unwrap-or-default, r=thomcc

Improve code example for Option::unwrap_or_default Fixes #100054. Follow-up of #102259. r? ``@thomcc``

Author: notriddle

library/core/src/option.rs

@@ -834,20 +834,12 @@ impl<T> Option<T> {
  ///
  /// # Examples
  ///
- /// Converts a string to an integer, turning poorly-formed strings
- /// into 0 (the default value for integers). [`parse`] converts
- /// a string to any other type that implements [`FromStr`], returning
- /// [`None`] on error.
- ///
  /// ```
- /// let good_year_from_input = "1909";
- /// let bad_year_from_input = "190blarg";
- /// // Result::ok() converts a Result<T> to an Option<T>
- /// let good_year = good_year_from_input.parse().ok().unwrap_or_default();
- /// let bad_year = bad_year_from_input.parse().ok().unwrap_or_default();
+ /// let x: Option<u32> = None;
+ /// let y: Option<u32> = Some(12);
  ///
- /// assert_eq!(1909, good_year);
- /// assert_eq!(0, bad_year);
+ /// assert_eq!(x.unwrap_or_default(), 0);
+ /// assert_eq!(y.unwrap_or_default(), 12);
  /// ```
  ///
  /// [default value]: Default::default