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Rollup merge of #138968 - Natural-selection1:update-Result-doc, r=Amanieu

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Update the index of Result to make the summary more comprehensive

fix #138966

This PR and #138957 are twin PR

r? `@Amanieu`
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Matthias Krüger 2025-04-25 17:31:46 +02:00 • committed by GitHub
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32
library/core/src/result.rs
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@ -259,8 +259,14 @@
//! The [`is_ok`] and [`is_err`] methods return [`true`] if the [`Result`]
//! is [`Ok`] or [`Err`], respectively.
//!
//! The [`is_ok_and`] and [`is_err_and`] methods apply the provided function
//! to the contents of the [`Result`] to produce a boolean value. If the [`Result`] does not have the expected variant
//! then [`false`] is returned instead without executing the function.
//!
//! [`is_err`]: Result::is_err
//! [`is_ok`]: Result::is_ok
//! [`is_ok_and`]: Result::is_ok_and
//! [`is_err_and`]: Result::is_err_and
//!
//! ## Adapters for working with references
//!
@ -287,6 +293,7 @@
//! (which must implement the [`Default`] trait)
//! * [`unwrap_or_else`] returns the result of evaluating the provided
//! function
//! * [`unwrap_unchecked`] produces *[undefined behavior]*
//!
//! The panicking methods [`expect`] and [`unwrap`] require `E` to
//! implement the [`Debug`] trait.
@ -297,6 +304,8 @@
//! [`unwrap_or`]: Result::unwrap_or
//! [`unwrap_or_default`]: Result::unwrap_or_default
//! [`unwrap_or_else`]: Result::unwrap_or_else
//! [`unwrap_unchecked`]: Result::unwrap_unchecked
//! [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html
//!
//! These methods extract the contained value in a [`Result<T, E>`] when it
//! is the [`Err`] variant. They require `T` to implement the [`Debug`]
@ -304,10 +313,13 @@
//!
//! * [`expect_err`] panics with a provided custom message
//! * [`unwrap_err`] panics with a generic message
//! * [`unwrap_err_unchecked`] produces *[undefined behavior]*
//!
//! [`Debug`]: crate::fmt::Debug
//! [`expect_err`]: Result::expect_err
//! [`unwrap_err`]: Result::unwrap_err
//! [`unwrap_err_unchecked`]: Result::unwrap_err_unchecked
//! [undefined behavior]: https://doc.rust-lang.org/reference/behavior-considered-undefined.html
//!
//! ## Transforming contained values
//!
@ -330,21 +342,29 @@
//! [`Some(v)`]: Option::Some
//! [`transpose`]: Result::transpose
//!
//! This method transforms the contained value of the [`Ok`] variant:
//! These methods transform the contained value of the [`Ok`] variant:
//!
//! * [`map`] transforms [`Result<T, E>`] into [`Result<U, E>`] by applying
//! the provided function to the contained value of [`Ok`] and leaving
//! [`Err`] values unchanged
//! * [`inspect`] takes ownership of the [`Result`], applies the
//! provided function to the contained value by reference,
//! and then returns the [`Result`]
//!
//! [`map`]: Result::map
//! [`inspect`]: Result::inspect
//!
//! This method transforms the contained value of the [`Err`] variant:
//! These methods transform the contained value of the [`Err`] variant:
//!
//! * [`map_err`] transforms [`Result<T, E>`] into [`Result<T, F>`] by
//! applying the provided function to the contained value of [`Err`] and
//! leaving [`Ok`] values unchanged
//! * [`inspect_err`] takes ownership of the [`Result`], applies the
//! provided function to the contained value of [`Err`] by reference,
//! and then returns the [`Result`]
//!
//! [`map_err`]: Result::map_err
//! [`inspect_err`]: Result::inspect_err
//!
//! These methods transform a [`Result<T, E>`] into a value of a possibly
//! different type `U`:
@ -578,6 +598,10 @@ impl<T, E> Result<T, E> {
///
/// let x: Result<u32, &str> = Err("hey");
/// assert_eq!(x.is_ok_and(|x| x > 1), false);
///
/// let x: Result<String, &str> = Ok("ownership".to_string());
/// assert_eq!(x.as_ref().is_ok_and(|x| x.len() > 1), true);
/// println!("still alive {:?}", x);
/// ```
#[must_use]
#[inline]
@ -623,6 +647,10 @@ impl<T, E> Result<T, E> {
///
/// let x: Result<u32, Error> = Ok(123);
/// assert_eq!(x.is_err_and(|x| x.kind() == ErrorKind::NotFound), false);
///
/// let x: Result<u32, String> = Err("ownership".to_string());
/// assert_eq!(x.as_ref().is_err_and(|x| x.len() > 1), true);
/// println!("still alive {:?}", x);
/// ```
#[must_use]
#[inline]