diff --git a/library/core/src/option.rs b/library/core/src/option.rs index 7ec0ac7127142..aed5a043c11a3 100644 --- a/library/core/src/option.rs +++ b/library/core/src/option.rs @@ -162,8 +162,14 @@ //! The [`is_some`] and [`is_none`] methods return [`true`] if the [`Option`] //! is [`Some`] or [`None`], respectively. //! +//! The [`is_some_and`] and [`is_none_or`] methods apply the provided function +//! to the contents of the [`Option`] to produce a boolean value. +//! If this is [`None`] then a default result is returned instead without executing the function. +//! //! [`is_none`]: Option::is_none //! [`is_some`]: Option::is_some +//! [`is_some_and`]: Option::is_some_and +//! [`is_none_or`]: Option::is_none_or //! //! ## Adapters for working with references //! @@ -177,6 +183,10 @@ //! [Option]<[Pin]<[&]T>> //! * [`as_pin_mut`] converts from [Pin]<[&mut] [Option]\> to //! [Option]<[Pin]<[&mut] T>> +//! * [`as_slice`] returns a one-element slice of the contained value, if any. +//! If this is [`None`], an empty slice is returned. +//! * [`as_mut_slice`] returns a mutable one-element slice of the contained value, if any. +//! If this is [`None`], an empty slice is returned. //! //! [&]: reference "shared reference" //! [&mut]: reference "mutable reference" @@ -187,6 +197,8 @@ //! [`as_pin_mut`]: Option::as_pin_mut //! [`as_pin_ref`]: Option::as_pin_ref //! [`as_ref`]: Option::as_ref +//! [`as_slice`]: Option::as_slice +//! [`as_mut_slice`]: Option::as_mut_slice //! //! ## Extracting the contained value //! @@ -200,12 +212,15 @@ //! (which must implement the [`Default`] trait) //! * [`unwrap_or_else`] returns the result of evaluating the provided //! function +//! * [`unwrap_unchecked`] produces *[undefined behavior]* //! //! [`expect`]: Option::expect //! [`unwrap`]: Option::unwrap //! [`unwrap_or`]: Option::unwrap_or //! [`unwrap_or_default`]: Option::unwrap_or_default //! [`unwrap_or_else`]: Option::unwrap_or_else +//! [`unwrap_unchecked`]: Option::unwrap_unchecked +//! [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html //! //! ## Transforming contained values //! @@ -230,8 +245,9 @@ //! * [`filter`] calls the provided predicate function on the contained //! value `t` if the [`Option`] is [`Some(t)`], and returns [`Some(t)`] //! if the function returns `true`; otherwise, returns [`None`] -//! * [`flatten`] removes one level of nesting from an -//! [`Option>`] +//! * [`flatten`] removes one level of nesting from an [`Option>`] +//! * [`inspect`] method takes ownership of the [`Option`] and applies +//! the provided function to the contained value by reference if [`Some`] //! * [`map`] transforms [`Option`] to [`Option`] by applying the //! provided function to the contained value of [`Some`] and leaving //! [`None`] values unchanged @@ -239,6 +255,7 @@ //! [`Some(t)`]: Some //! [`filter`]: Option::filter //! [`flatten`]: Option::flatten +//! [`inspect`]: Option::inspect //! [`map`]: Option::map //! //! These methods transform [`Option`] to a value of a possibly @@ -621,6 +638,10 @@ impl Option { /// /// let x: Option = None; /// assert_eq!(x.is_some_and(|x| x > 1), false); + /// + /// let x: Option = Some("ownership".to_string()); + /// assert_eq!(x.as_ref().is_some_and(|x| x.len() > 1), true); + /// println!("still alive {:?}", x); /// ``` #[must_use] #[inline] @@ -665,6 +686,10 @@ impl Option { /// /// let x: Option = None; /// assert_eq!(x.is_none_or(|x| x > 1), true); + /// + /// let x: Option = Some("ownership".to_string()); + /// assert_eq!(x.as_ref().is_none_or(|x| x.len() > 1), true); + /// println!("still alive {:?}", x); /// ``` #[must_use] #[inline]