Auto merge of rust-lang#106621 - ozkanonur:enable-elided-lifetimes-for-doctests, r=Mark-Simulacrum

enable `rust_2018_idioms` lint group for doctests

With this change, `rust_2018_idioms` lint group will be enabled for compiler/libstd doctests.

Resolves rust-lang#106086
Resolves rust-lang#99144

Signed-off-by: ozkanonur <[email protected]>

Author: bors

alloc/src/borrow.rs

@@ -115,7 +115,7 @@ where
 /// ```
 /// use std::borrow::Cow;
 ///
-/// fn abs_all(input: &mut Cow<[i32]>) {
+/// fn abs_all(input: &mut Cow<'_, [i32]>) {
 ///     for i in 0..input.len() {
 ///         let v = input[i];
 ///         if v < 0 {
@@ -145,7 +145,7 @@ where
 /// ```
 /// use std::borrow::Cow;
 ///
-/// struct Items<'a, X: 'a> where [X]: ToOwned<Owned = Vec<X>> {
+/// struct Items<'a, X> where [X]: ToOwned<Owned = Vec<X>> {
 ///     values: Cow<'a, [X]>,
 /// }
 ///
@@ -267,7 +267,7 @@ impl<B: ?Sized + ToOwned> Cow<'_, B> {
     ///
     /// assert_eq!(
     ///   cow,
-    ///   Cow::Owned(String::from("FOO")) as Cow<str>
+    ///   Cow::Owned(String::from("FOO")) as Cow<'_, str>
     /// );
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -311,7 +311,7 @@ impl<B: ?Sized + ToOwned> Cow<'_, B> {
     /// use std::borrow::Cow;
     ///
     /// let s = "Hello world!";
-    /// let cow: Cow<str> = Cow::Owned(String::from(s));
+    /// let cow: Cow<'_, str> = Cow::Owned(String::from(s));
     ///
     /// assert_eq!(
     ///   cow.into_owned(),

alloc/src/fmt.rs

@@ -363,7 +363,7 @@
 //! # use std::fmt;
 //! # struct Foo; // our custom type
 //! # impl fmt::Display for Foo {
-//! fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+//! fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 //! # write!(f, "testing, testing")
 //! # } }
 //! ```
@@ -399,7 +399,7 @@
 //! }
 //!
 //! impl fmt::Display for Vector2D {
-//!     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+//!     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 //!         // The `f` value implements the `Write` trait, which is what the
 //!         // write! macro is expecting. Note that this formatting ignores the
 //!         // various flags provided to format strings.
@@ -410,7 +410,7 @@
 //! // Different traits allow different forms of output of a type. The meaning
 //! // of this format is to print the magnitude of a vector.
 //! impl fmt::Binary for Vector2D {
-//!     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+//!     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 //!         let magnitude = (self.x * self.x + self.y * self.y) as f64;
 //!         let magnitude = magnitude.sqrt();
 //!
@@ -517,7 +517,7 @@
 //! let mut some_writer = io::stdout();
 //! write!(&mut some_writer, "{}", format_args!("print with a {}", "macro"));
 //!
-//! fn my_fmt_fn(args: fmt::Arguments) {
+//! fn my_fmt_fn(args: fmt::Arguments<'_>) {
 //!     write!(&mut io::stdout(), "{args}");
 //! }
 //! my_fmt_fn(format_args!(", or a {} too", "function"));

alloc/src/rc.rs

@@ -2039,7 +2039,7 @@ where
     /// ```rust
     /// # use std::rc::Rc;
     /// # use std::borrow::Cow;
-    /// let cow: Cow<str> = Cow::Borrowed("eggplant");
+    /// let cow: Cow<'_, str> = Cow::Borrowed("eggplant");
     /// let shared: Rc<str> = Rc::from(cow);
     /// assert_eq!("eggplant", &shared[..]);
     /// ```

alloc/src/string.rs

@@ -2741,7 +2741,7 @@ impl<'a> From<Cow<'a, str>> for String {
     /// ```
     /// # use std::borrow::Cow;
     /// // If the string is not owned...
-    /// let cow: Cow<str> = Cow::Borrowed("eggplant");
+    /// let cow: Cow<'_, str> = Cow::Borrowed("eggplant");
     /// // It will allocate on the heap and copy the string.
     /// let owned: String = String::from(cow);
     /// assert_eq!(&owned[..], "eggplant");

alloc/src/sync.rs

@@ -2768,7 +2768,7 @@ where
     /// ```rust
     /// # use std::sync::Arc;
     /// # use std::borrow::Cow;
-    /// let cow: Cow<str> = Cow::Borrowed("eggplant");
+    /// let cow: Cow<'_, str> = Cow::Borrowed("eggplant");
     /// let shared: Arc<str> = Arc::from(cow);
     /// assert_eq!("eggplant", &shared[..]);
     /// ```

alloc/src/vec/drain.rs

@@ -16,7 +16,7 @@ use super::Vec;
 ///
 /// ```
 /// let mut v = vec![0, 1, 2];
-/// let iter: std::vec::Drain<_> = v.drain(..);
+/// let iter: std::vec::Drain<'_, _> = v.drain(..);
 /// ```
 #[stable(feature = "drain", since = "1.6.0")]
 pub struct Drain<

alloc/src/vec/drain_filter.rs

@@ -16,7 +16,7 @@ use super::Vec;
 /// #![feature(drain_filter)]
 ///
 /// let mut v = vec![0, 1, 2];
-/// let iter: std::vec::DrainFilter<_, _> = v.drain_filter(|x| *x % 2 == 0);
+/// let iter: std::vec::DrainFilter<'_, _, _> = v.drain_filter(|x| *x % 2 == 0);
 /// ```
 #[unstable(feature = "drain_filter", reason = "recently added", issue = "43244")]
 #[derive(Debug)]

alloc/src/vec/mod.rs

@@ -3142,8 +3142,8 @@ where
     ///
     /// ```
     /// # use std::borrow::Cow;
-    /// let o: Cow<[i32]> = Cow::Owned(vec![1, 2, 3]);
-    /// let b: Cow<[i32]> = Cow::Borrowed(&[1, 2, 3]);
+    /// let o: Cow<'_, [i32]> = Cow::Owned(vec![1, 2, 3]);
+    /// let b: Cow<'_, [i32]> = Cow::Borrowed(&[1, 2, 3]);
     /// assert_eq!(Vec::from(o), Vec::from(b));
     /// ```
     fn from(s: Cow<'a, [T]>) -> Vec<T> {

alloc/src/vec/splice.rs

@@ -14,7 +14,7 @@ use super::{Drain, Vec};
 /// ```
 /// let mut v = vec![0, 1, 2];
 /// let new = [7, 8];
-/// let iter: std::vec::Splice<_> = v.splice(1.., new);
+/// let iter: std::vec::Splice<'_, _> = v.splice(1.., new);
 /// ```
 #[derive(Debug)]
 #[stable(feature = "vec_splice", since = "1.21.0")]

core/src/cell.rs

@@ -115,7 +115,7 @@
 //!     let shared_map: Rc<RefCell<_>> = Rc::new(RefCell::new(HashMap::new()));
 //!     // Create a new block to limit the scope of the dynamic borrow
 //!     {
-//!         let mut map: RefMut<_> = shared_map.borrow_mut();
+//!         let mut map: RefMut<'_, _> = shared_map.borrow_mut();
 //!         map.insert("africa", 92388);
 //!         map.insert("kyoto", 11837);
 //!         map.insert("piccadilly", 11826);
@@ -1435,8 +1435,8 @@ impl<'b, T: ?Sized> Ref<'b, T> {
     /// use std::cell::{RefCell, Ref};
     ///
     /// let c = RefCell::new((5, 'b'));
-    /// let b1: Ref<(u32, char)> = c.borrow();
-    /// let b2: Ref<u32> = Ref::map(b1, |t| &t.0);
+    /// let b1: Ref<'_, (u32, char)> = c.borrow();
+    /// let b2: Ref<'_, u32> = Ref::map(b1, |t| &t.0);
     /// assert_eq!(*b2, 5)
     /// ```
     #[stable(feature = "cell_map", since = "1.8.0")]
@@ -1464,8 +1464,8 @@ impl<'b, T: ?Sized> Ref<'b, T> {
     /// use std::cell::{RefCell, Ref};
     ///
     /// let c = RefCell::new(vec![1, 2, 3]);
-    /// let b1: Ref<Vec<u32>> = c.borrow();
-    /// let b2: Result<Ref<u32>, _> = Ref::filter_map(b1, |v| v.get(1));
+    /// let b1: Ref<'_, Vec<u32>> = c.borrow();
+    /// let b2: Result<Ref<'_, u32>, _> = Ref::filter_map(b1, |v| v.get(1));
     /// assert_eq!(*b2.unwrap(), 2);
     /// ```
     #[stable(feature = "cell_filter_map", since = "1.63.0")]
@@ -1577,8 +1577,8 @@ impl<'b, T: ?Sized> RefMut<'b, T> {
     ///
     /// let c = RefCell::new((5, 'b'));
     /// {
-    ///     let b1: RefMut<(u32, char)> = c.borrow_mut();
-    ///     let mut b2: RefMut<u32> = RefMut::map(b1, |t| &mut t.0);
+    ///     let b1: RefMut<'_, (u32, char)> = c.borrow_mut();
+    ///     let mut b2: RefMut<'_, u32> = RefMut::map(b1, |t| &mut t.0);
     ///     assert_eq!(*b2, 5);
     ///     *b2 = 42;
     /// }
@@ -1612,8 +1612,8 @@ impl<'b, T: ?Sized> RefMut<'b, T> {
     /// let c = RefCell::new(vec![1, 2, 3]);
     ///
     /// {
-    ///     let b1: RefMut<Vec<u32>> = c.borrow_mut();
-    ///     let mut b2: Result<RefMut<u32>, _> = RefMut::filter_map(b1, |v| v.get_mut(1));
+    ///     let b1: RefMut<'_, Vec<u32>> = c.borrow_mut();
+    ///     let mut b2: Result<RefMut<'_, u32>, _> = RefMut::filter_map(b1, |v| v.get_mut(1));
     ///
     ///     if let Ok(mut b2) = b2 {
     ///         *b2 += 2;