Rollup merge of #76867 - poliorcetics:intra-doc-core-iter, r=jyn514

Use intra-doc links in core/src/iter when possible

Helps with #75080.

I also updated lots of links to use `fn()` instead of `fn` when possible.

@rustbot modify labels: T-doc A-intra-doc-links

r? @jyn514

Author: RalfJung

library/core/src/iter/sources.rs

@@ -5,9 +5,7 @@ use super::{FusedIterator, TrustedLen};
 
 /// An iterator that repeats an element endlessly.
 ///
-/// This `struct` is created by the [`repeat`] function. See its documentation for more.
-///
-/// [`repeat`]: fn.repeat.html
+/// This `struct` is created by the [`repeat()`] function. See its documentation for more.
 #[derive(Clone, Debug)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Repeat<A> {
@@ -47,15 +45,11 @@ unsafe impl<A: Clone> TrustedLen for Repeat<A> {}
 /// The `repeat()` function repeats a single value over and over again.
 ///
 /// Infinite iterators like `repeat()` are often used with adapters like
-/// [`take`], in order to make them finite.
-///
-/// [`take`]: trait.Iterator.html#method.take
+/// [`Iterator::take()`], in order to make them finite.
 ///
 /// If the element type of the iterator you need does not implement `Clone`,
 /// or if you do not want to keep the repeated element in memory, you can
-/// instead use the [`repeat_with`] function.
-///
-/// [`repeat_with`]: fn.repeat_with.html
+/// instead use the [`repeat_with()`] function.
 ///
 /// # Examples
 ///
@@ -77,7 +71,7 @@ unsafe impl<A: Clone> TrustedLen for Repeat<A> {}
 /// assert_eq!(Some(4), fours.next());
 /// ```
 ///
-/// Going finite with [`take`]:
+/// Going finite with [`Iterator::take()`]:
 ///
 /// ```
 /// use std::iter;
@@ -102,10 +96,8 @@ pub fn repeat<T: Clone>(elt: T) -> Repeat<T> {
 /// An iterator that repeats elements of type `A` endlessly by
 /// applying the provided closure `F: FnMut() -> A`.
 ///
-/// This `struct` is created by the [`repeat_with`] function.
+/// This `struct` is created by the [`repeat_with()`] function.
 /// See its documentation for more.
-///
-/// [`repeat_with`]: fn.repeat_with.html
 #[derive(Copy, Clone, Debug)]
 #[stable(feature = "iterator_repeat_with", since = "1.28.0")]
 pub struct RepeatWith<F> {
@@ -139,20 +131,18 @@ unsafe impl<A, F: FnMut() -> A> TrustedLen for RepeatWith<F> {}
 /// The `repeat_with()` function calls the repeater over and over again.
 ///
 /// Infinite iterators like `repeat_with()` are often used with adapters like
-/// [`take`], in order to make them finite.
-///
-/// [`take`]: trait.Iterator.html#method.take
+/// [`Iterator::take()`], in order to make them finite.
 ///
-/// If the element type of the iterator you need implements `Clone`, and
+/// If the element type of the iterator you need implements [`Clone`], and
 /// it is OK to keep the source element in memory, you should instead use
-/// the [`repeat`] function.
-///
-/// [`repeat`]: fn.repeat.html
+/// the [`repeat()`] function.
 ///
-/// An iterator produced by `repeat_with()` is not a `DoubleEndedIterator`.
-/// If you need `repeat_with()` to return a `DoubleEndedIterator`,
+/// An iterator produced by `repeat_with()` is not a [`DoubleEndedIterator`].
+/// If you need `repeat_with()` to return a [`DoubleEndedIterator`],
 /// please open a GitHub issue explaining your use case.
 ///
+/// [`DoubleEndedIterator`]: crate::iter::DoubleEndedIterator
+///
 /// # Examples
 ///
 /// Basic usage:
@@ -201,9 +191,7 @@ pub fn repeat_with<A, F: FnMut() -> A>(repeater: F) -> RepeatWith<F> {
 
 /// An iterator that yields nothing.
 ///
-/// This `struct` is created by the [`empty`] function. See its documentation for more.
-///
-/// [`empty`]: fn.empty.html
+/// This `struct` is created by the [`empty()`] function. See its documentation for more.
 #[stable(feature = "iter_empty", since = "1.2.0")]
 pub struct Empty<T>(marker::PhantomData<T>);
 
@@ -292,9 +280,7 @@ pub const fn empty<T>() -> Empty<T> {
 
 /// An iterator that yields an element exactly once.
 ///
-/// This `struct` is created by the [`once`] function. See its documentation for more.
-///
-/// [`once`]: fn.once.html
+/// This `struct` is created by the [`once()`] function. See its documentation for more.
 #[derive(Clone, Debug)]
 #[stable(feature = "iter_once", since = "1.2.0")]
 pub struct Once<T> {
@@ -336,12 +322,12 @@ impl<T> FusedIterator for Once<T> {}
 
 /// Creates an iterator that yields an element exactly once.
 ///
-/// This is commonly used to adapt a single value into a [`chain`] of other
+/// This is commonly used to adapt a single value into a [`chain()`] of other
 /// kinds of iteration. Maybe you have an iterator that covers almost
 /// everything, but you need an extra special case. Maybe you have a function
 /// which works on iterators, but you only need to process one value.
 ///
-/// [`chain`]: trait.Iterator.html#method.chain
+/// [`chain()`]: Iterator::chain
 ///
 /// # Examples
 ///
@@ -393,10 +379,8 @@ pub fn once<T>(value: T) -> Once<T> {
 /// An iterator that yields a single element of type `A` by
 /// applying the provided closure `F: FnOnce() -> A`.
 ///
-/// This `struct` is created by the [`once_with`] function.
+/// This `struct` is created by the [`once_with()`] function.
 /// See its documentation for more.
-///
-/// [`once_with`]: fn.once_with.html
 #[derive(Clone, Debug)]
 #[stable(feature = "iter_once_with", since = "1.43.0")]
 pub struct OnceWith<F> {
@@ -442,15 +426,14 @@ unsafe impl<A, F: FnOnce() -> A> TrustedLen for OnceWith<F> {}
 /// Creates an iterator that lazily generates a value exactly once by invoking
 /// the provided closure.
 ///
-/// This is commonly used to adapt a single value generator into a [`chain`] of
+/// This is commonly used to adapt a single value generator into a [`chain()`] of
 /// other kinds of iteration. Maybe you have an iterator that covers almost
 /// everything, but you need an extra special case. Maybe you have a function
 /// which works on iterators, but you only need to process one value.
 ///
-/// Unlike [`once`], this function will lazily generate the value on request.
+/// Unlike [`once()`], this function will lazily generate the value on request.
 ///
-/// [`once`]: fn.once.html
-/// [`chain`]: trait.Iterator.html#method.chain
+/// [`chain()`]: Iterator::chain
 ///
 /// # Examples
 ///
@@ -505,17 +488,16 @@ pub fn once_with<A, F: FnOnce() -> A>(gen: F) -> OnceWith<F> {
 ///
 /// This allows creating a custom iterator with any behavior
 /// without using the more verbose syntax of creating a dedicated type
-/// and implementing the `Iterator` trait for it.
+/// and implementing the [`Iterator`] trait for it.
 ///
 /// Note that the `FromFn` iterator doesn’t make assumptions about the behavior of the closure,
 /// and therefore conservatively does not implement [`FusedIterator`],
-/// or override [`Iterator::size_hint`] from its default `(0, None)`.
-///
-/// [`FusedIterator`]: trait.FusedIterator.html
-/// [`Iterator::size_hint`]: trait.Iterator.html#method.size_hint
+/// or override [`Iterator::size_hint()`] from its default `(0, None)`.
 ///
 /// The closure can use captures and its environment to track state across iterations. Depending on
-/// how the iterator is used, this may require specifying the `move` keyword on the closure.
+/// how the iterator is used, this may require specifying the [`move`] keyword on the closure.
+///
+/// [`move`]: ../../std/keyword.move.html
 ///
 /// # Examples
 ///
@@ -549,10 +531,10 @@ where
 
 /// An iterator where each iteration calls the provided closure `F: FnMut() -> Option<T>`.
 ///
-/// This `struct` is created by the [`iter::from_fn`] function.
+/// This `struct` is created by the [`iter::from_fn()`] function.
 /// See its documentation for more.
 ///
-/// [`iter::from_fn`]: fn.from_fn.html
+/// [`iter::from_fn()`]: from_fn
 #[derive(Clone)]
 #[stable(feature = "iter_from_fn", since = "1.34.0")]
 pub struct FromFn<F>(F);
@@ -601,10 +583,10 @@ where
 
 /// An new iterator where each successive item is computed based on the preceding one.
 ///
-/// This `struct` is created by the [`successors`] function.
+/// This `struct` is created by the [`iter::successors()`] function.
 /// See its documentation for more.
 ///
-/// [`successors`]: fn.successors.html
+/// [`iter::successors()`]: successors
 #[derive(Clone)]
 #[stable(feature = "iter_successors", since = "1.34.0")]
 pub struct Successors<T, F> {

library/core/src/iter/traits/accum.rs

@@ -4,14 +4,13 @@ use crate::ops::{Add, Mul};
 
 /// Trait to represent types that can be created by summing up an iterator.
 ///
-/// This trait is used to implement the [`sum`] method on iterators. Types which
-/// implement the trait can be generated by the [`sum`] method. Like
+/// This trait is used to implement the [`sum()`] method on iterators. Types which
+/// implement the trait can be generated by the [`sum()`] method. Like
 /// [`FromIterator`] this trait should rarely be called directly and instead
-/// interacted with through [`Iterator::sum`].
+/// interacted with through [`Iterator::sum()`].
 ///
-/// [`sum`]: #tymethod.sum
-/// [`FromIterator`]: crate::iter::FromIterator
-/// [`Iterator::sum`]: crate::iter::Iterator::sum
+/// [`sum()`]: Sum::sum
+/// [`FromIterator`]: iter::FromIterator
 #[stable(feature = "iter_arith_traits", since = "1.12.0")]
 pub trait Sum<A = Self>: Sized {
     /// Method which takes an iterator and generates `Self` from the elements by
@@ -23,14 +22,13 @@ pub trait Sum<A = Self>: Sized {
 /// Trait to represent types that can be created by multiplying elements of an
 /// iterator.
 ///
-/// This trait is used to implement the [`product`] method on iterators. Types
-/// which implement the trait can be generated by the [`product`] method. Like
+/// This trait is used to implement the [`product()`] method on iterators. Types
+/// which implement the trait can be generated by the [`product()`] method. Like
 /// [`FromIterator`] this trait should rarely be called directly and instead
-/// interacted with through [`Iterator::product`].
+/// interacted with through [`Iterator::product()`].
 ///
-/// [`product`]: #tymethod.product
-/// [`FromIterator`]: crate::iter::FromIterator
-/// [`Iterator::product`]: crate::iter::Iterator::product
+/// [`product()`]: Product::product
+/// [`FromIterator`]: iter::FromIterator
 #[stable(feature = "iter_arith_traits", since = "1.12.0")]
 pub trait Product<A = Self>: Sized {
     /// Method which takes an iterator and generates `Self` from the elements by
@@ -120,9 +118,9 @@ impl<T, U, E> Sum<Result<U, E>> for Result<T, E>
 where
     T: Sum<U>,
 {
-    /// Takes each element in the `Iterator`: if it is an `Err`, no further
-    /// elements are taken, and the `Err` is returned. Should no `Err` occur,
-    /// the sum of all elements is returned.
+    /// Takes each element in the [`Iterator`]: if it is an [`Err`], no further
+    /// elements are taken, and the [`Err`] is returned. Should no [`Err`]
+    /// occur, the sum of all elements is returned.
     ///
     /// # Examples
     ///
@@ -150,9 +148,9 @@ impl<T, U, E> Product<Result<U, E>> for Result<T, E>
 where
     T: Product<U>,
 {
-    /// Takes each element in the `Iterator`: if it is an `Err`, no further
-    /// elements are taken, and the `Err` is returned. Should no `Err` occur,
-    /// the product of all elements is returned.
+    /// Takes each element in the [`Iterator`]: if it is an [`Err`], no further
+    /// elements are taken, and the [`Err`] is returned. Should no [`Err`]
+    /// occur, the product of all elements is returned.
     fn product<I>(iter: I) -> Result<T, E>
     where
         I: Iterator<Item = Result<U, E>>,
@@ -166,9 +164,9 @@ impl<T, U> Sum<Option<U>> for Option<T>
 where
     T: Sum<U>,
 {
-    /// Takes each element in the `Iterator`: if it is a `None`, no further
-    /// elements are taken, and the `None` is returned. Should no `None` occur,
-    /// the sum of all elements is returned.
+    /// Takes each element in the [`Iterator`]: if it is a [`None`], no further
+    /// elements are taken, and the [`None`] is returned. Should no [`None`]
+    /// occur, the sum of all elements is returned.
     ///
     /// # Examples
     ///
@@ -193,9 +191,9 @@ impl<T, U> Product<Option<U>> for Option<T>
 where
     T: Product<U>,
 {
-    /// Takes each element in the `Iterator`: if it is a `None`, no further
-    /// elements are taken, and the `None` is returned. Should no `None` occur,
-    /// the product of all elements is returned.
+    /// Takes each element in the [`Iterator`]: if it is a [`None`], no further
+    /// elements are taken, and the [`None`] is returned. Should no [`None`]
+    /// occur, the product of all elements is returned.
     fn product<I>(iter: I) -> Option<T>
     where
         I: Iterator<Item = Option<U>>,

library/core/src/iter/traits/collect.rs

@@ -1,21 +1,15 @@
-/// Conversion from an `Iterator`.
+/// Conversion from an [`Iterator`].
 ///
 /// By implementing `FromIterator` for a type, you define how it will be
 /// created from an iterator. This is common for types which describe a
 /// collection of some kind.
 ///
-/// `FromIterator`'s [`from_iter`] is rarely called explicitly, and is instead
-/// used through [`Iterator`]'s [`collect`] method. See [`collect`]'s
+/// [`FromIterator::from_iter()`] is rarely called explicitly, and is instead
+/// used through [`Iterator::collect()`] method. See [`Iterator::collect()`]'s
 /// documentation for more examples.
 ///
-/// [`from_iter`]: #tymethod.from_iter
-/// [`Iterator`]: trait.Iterator.html
-/// [`collect`]: trait.Iterator.html#method.collect
-///
 /// See also: [`IntoIterator`].
 ///
-/// [`IntoIterator`]: trait.IntoIterator.html
-///
 /// # Examples
 ///
 /// Basic usage:
@@ -30,7 +24,7 @@
 /// assert_eq!(v, vec![5, 5, 5, 5, 5]);
 /// ```
 ///
-/// Using [`collect`] to implicitly use `FromIterator`:
+/// Using [`Iterator::collect()`] to implicitly use `FromIterator`:
 ///
 /// ```
 /// let five_fives = std::iter::repeat(5).take(5);
@@ -119,7 +113,7 @@ pub trait FromIterator<A>: Sized {
     fn from_iter<T: IntoIterator<Item = A>>(iter: T) -> Self;
 }
 
-/// Conversion into an `Iterator`.
+/// Conversion into an [`Iterator`].
 ///
 /// By implementing `IntoIterator` for a type, you define how it will be
 /// converted to an iterator. This is common for types which describe a
@@ -130,8 +124,6 @@ pub trait FromIterator<A>: Sized {
 ///
 /// See also: [`FromIterator`].
 ///
-/// [`FromIterator`]: trait.FromIterator.html
-///
 /// # Examples
 ///
 /// Basic usage:
@@ -326,7 +318,7 @@ pub trait Extend<A> {
     /// As this is the only required method for this trait, the [trait-level] docs
     /// contain more details.
     ///
-    /// [trait-level]: trait.Extend.html
+    /// [trait-level]: Extend
     ///
     /// # Examples
     ///