Auto merge of #59293 - Centril:rollup, r=Centril

Rollup of 11 pull requests

Successful merges:

 - #56348 (Add todo!() macro)
 - #57729 (extra testing of how NLL handles wildcard type `_`)
 - #57847 (dbg!() without parameters)
 - #58778 (Implement ExactSizeIterator for ToLowercase and ToUppercase)
 - #58812 (Clarify distinction between floor() and trunc())
 - #58939 (Fix a tiny error in documentation of std::pin.)
 - #59116 (Be more discerning on when to attempt suggesting a comma in a macro invocation)
 - #59252 (add self to mailmap)
 - #59275 (Replaced self-reflective explicit types with clearer `Self` or `Self::…` in stdlib docs)
 - #59280 (Stabilize refcell_map_split feature)
 - #59290 (Run branch cleanup after copy prop)

Failed merges:

r? @ghost

Author: bors

.mailmap

@@ -29,6 +29,7 @@ Ariel Ben-Yehuda <[email protected]> Ariel Ben-Yehuda <[email protected]>
 Ariel Ben-Yehuda <[email protected]> arielb1 <[email protected]>
 Austin Seipp <[email protected]> <[email protected]>
 Aydin Kim <[email protected]> aydin.kim <[email protected]>
+Bastian Kauschke <[email protected]>
 Barosl Lee <[email protected]> Barosl LEE <[email protected]>
 Ben Alpert <[email protected]> <[email protected]>
 Ben Sago <[email protected]> Ben S <[email protected]>

src/libcore/cell.rs

@@ -1186,7 +1186,6 @@ impl<'b, T: ?Sized> Ref<'b, T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(refcell_map_split)]
     /// use std::cell::{Ref, RefCell};
     ///
     /// let cell = RefCell::new([1, 2, 3, 4]);
@@ -1195,7 +1194,7 @@ impl<'b, T: ?Sized> Ref<'b, T> {
     /// assert_eq!(*begin, [1, 2]);
     /// assert_eq!(*end, [3, 4]);
     /// ```
-    #[unstable(feature = "refcell_map_split", issue = "51476")]
+    #[stable(feature = "refcell_map_split", since = "1.35.0")]
     #[inline]
     pub fn map_split<U: ?Sized, V: ?Sized, F>(orig: Ref<'b, T>, f: F) -> (Ref<'b, U>, Ref<'b, V>)
         where F: FnOnce(&T) -> (&U, &V)
@@ -1268,7 +1267,6 @@ impl<'b, T: ?Sized> RefMut<'b, T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(refcell_map_split)]
     /// use std::cell::{RefCell, RefMut};
     ///
     /// let cell = RefCell::new([1, 2, 3, 4]);
@@ -1279,7 +1277,7 @@ impl<'b, T: ?Sized> RefMut<'b, T> {
     /// begin.copy_from_slice(&[4, 3]);
     /// end.copy_from_slice(&[2, 1]);
     /// ```
-    #[unstable(feature = "refcell_map_split", issue = "51476")]
+    #[stable(feature = "refcell_map_split", since = "1.35.0")]
     #[inline]
     pub fn map_split<U: ?Sized, V: ?Sized, F>(
         orig: RefMut<'b, T>, f: F

src/libcore/char/mod.rs

@@ -389,11 +389,17 @@ impl Iterator for ToLowercase {
     fn next(&mut self) -> Option<char> {
         self.0.next()
     }
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.0.size_hint()
+    }
 }
 
 #[stable(feature = "fused", since = "1.26.0")]
 impl FusedIterator for ToLowercase {}
 
+#[stable(feature = "exact_size_case_mapping_iter", since = "1.35.0")]
+impl ExactSizeIterator for ToLowercase {}
+
 /// Returns an iterator that yields the uppercase equivalent of a `char`.
 ///
 /// This `struct` is created by the [`to_uppercase`] method on [`char`]. See
@@ -411,11 +417,17 @@ impl Iterator for ToUppercase {
     fn next(&mut self) -> Option<char> {
         self.0.next()
     }
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.0.size_hint()
+    }
 }
 
 #[stable(feature = "fused", since = "1.26.0")]
 impl FusedIterator for ToUppercase {}
 
+#[stable(feature = "exact_size_case_mapping_iter", since = "1.35.0")]
+impl ExactSizeIterator for ToUppercase {}
+
 #[derive(Debug, Clone)]
 enum CaseMappingIter {
     Three(char, char, char),
@@ -457,6 +469,16 @@ impl Iterator for CaseMappingIter {
             CaseMappingIter::Zero => None,
         }
     }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let size = match self {
+            CaseMappingIter::Three(..) => 3,
+            CaseMappingIter::Two(..) => 2,
+            CaseMappingIter::One(_) => 1,
+            CaseMappingIter::Zero => 0,
+        };
+        (size, Some(size))
+    }
 }
 
 impl fmt::Display for CaseMappingIter {

src/libcore/cmp.rs

@@ -72,7 +72,7 @@ use self::Ordering::*;
 /// }
 ///
 /// impl PartialEq for Book {
-///     fn eq(&self, other: &Book) -> bool {
+///     fn eq(&self, other: &Self) -> bool {
 ///         self.isbn == other.isbn
 ///     }
 /// }
@@ -233,7 +233,7 @@ pub trait PartialEq<Rhs: ?Sized = Self> {
 ///     format: BookFormat,
 /// }
 /// impl PartialEq for Book {
-///     fn eq(&self, other: &Book) -> bool {
+///     fn eq(&self, other: &Self) -> bool {
 ///         self.isbn == other.isbn
 ///     }
 /// }
@@ -493,19 +493,19 @@ impl<T: Ord> Ord for Reverse<T> {
 /// }
 ///
 /// impl Ord for Person {
-///     fn cmp(&self, other: &Person) -> Ordering {
+///     fn cmp(&self, other: &Self) -> Ordering {
 ///         self.height.cmp(&other.height)
 ///     }
 /// }
 ///
 /// impl PartialOrd for Person {
-///     fn partial_cmp(&self, other: &Person) -> Option<Ordering> {
+///     fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
 ///         Some(self.cmp(other))
 ///     }
 /// }
 ///
 /// impl PartialEq for Person {
-///     fn eq(&self, other: &Person) -> bool {
+///     fn eq(&self, other: &Self) -> bool {
 ///         self.height == other.height
 ///     }
 /// }
@@ -691,13 +691,13 @@ impl PartialOrd for Ordering {
 /// }
 ///
 /// impl PartialOrd for Person {
-///     fn partial_cmp(&self, other: &Person) -> Option<Ordering> {
+///     fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
 ///         self.height.partial_cmp(&other.height)
 ///     }
 /// }
 ///
 /// impl PartialEq for Person {
-///     fn eq(&self, other: &Person) -> bool {
+///     fn eq(&self, other: &Self) -> bool {
 ///         self.height == other.height
 ///     }
 /// }

src/libcore/iter/mod.rs

@@ -101,7 +101,7 @@
 //!     type Item = usize;
 //!
 //!     // next() is the only required method
-//!     fn next(&mut self) -> Option<usize> {
+//!     fn next(&mut self) -> Option<Self::Item> {
 //!         // Increment our count. This is why we started at zero.
 //!         self.count += 1;
 //!

src/libcore/iter/traits/collect.rs

@@ -167,7 +167,7 @@ pub trait FromIterator<A>: Sized {
 /// // and we'll implement IntoIterator
 /// impl IntoIterator for MyCollection {
 ///     type Item = i32;
-///     type IntoIter = ::std::vec::IntoIter<i32>;
+///     type IntoIter = ::std::vec::IntoIter<Self::Item>;
 ///
 ///     fn into_iter(self) -> Self::IntoIter {
 ///         self.0.into_iter()

src/libcore/iter/traits/exact_size.rs

@@ -45,7 +45,7 @@
 /// # }
 /// # impl Iterator for Counter {
 /// #     type Item = usize;
-/// #     fn next(&mut self) -> Option<usize> {
+/// #     fn next(&mut self) -> Option<Self::Item> {
 /// #         self.count += 1;
 /// #         if self.count < 6 {
 /// #             Some(self.count)

src/libcore/macros.rs

@@ -559,6 +559,65 @@ macro_rules! unimplemented {
     ($($arg:tt)+) => (panic!("not yet implemented: {}", format_args!($($arg)*)));
 }
 
+/// A standardized placeholder for marking unfinished code.
+///
+/// This can be useful if you are prototyping and are just looking to have your
+/// code typecheck. `todo!` works exactly like `unimplemented!`, there only
+/// difference between the two macros is the name.
+///
+/// # Panics
+///
+/// This will always [panic!](macro.panic.html)
+///
+/// # Examples
+///
+/// Here's an example of some in-progress code. We have a trait `Foo`:
+///
+/// ```
+/// trait Foo {
+///     fn bar(&self);
+///     fn baz(&self);
+/// }
+/// ```
+///
+/// We want to implement `Foo` on one of our types, but we also want to work on
+/// just `bar()` first. In order for our code to compile, we need to implement
+/// `baz()`, so we can use `todo!`:
+///
+/// ```
+/// #![feature(todo_macro)]
+///
+/// # trait Foo {
+/// #     fn bar(&self);
+/// #     fn baz(&self);
+/// # }
+/// struct MyStruct;
+///
+/// impl Foo for MyStruct {
+///     fn bar(&self) {
+///         // implementation goes here
+///     }
+///
+///     fn baz(&self) {
+///         // let's not worry about implementing baz() for now
+///         todo!();
+///     }
+/// }
+///
+/// fn main() {
+///     let s = MyStruct;
+///     s.bar();
+///
+///     // we aren't even using baz() yet, so this is fine.
+/// }
+/// ```
+#[macro_export]
+#[unstable(feature = "todo_macro", issue = "59277")]
+macro_rules! todo {
+    () => (panic!("not yet implemented"));
+    ($($arg:tt)+) => (panic!("not yet implemented: {}", format_args!($($arg)*)));
+}
+
 /// A macro to create an array of [`MaybeUninit`]
 ///
 /// This macro constructs an uninitialized array of the type `[MaybeUninit<K>; N]`.

src/libcore/ops/arith.rs

@@ -20,10 +20,10 @@
 /// }
 ///
 /// impl Add for Point {
-///     type Output = Point;
+///     type Output = Self;
 ///
-///     fn add(self, other: Point) -> Point {
-///         Point {
+///     fn add(self, other: Self) -> Self {
+///         Self {
 ///             x: self.x + other.x,
 ///             y: self.y + other.y,
 ///         }
@@ -50,10 +50,10 @@
 ///
 /// // Notice that the implementation uses the associated type `Output`.
 /// impl<T: Add<Output = T>> Add for Point<T> {
-///     type Output = Point<T>;
+///     type Output = Self;
 ///
-///     fn add(self, other: Point<T>) -> Point<T> {
-///         Point {
+///     fn add(self, other: Self) -> Self::Output {
+///         Self {
 ///             x: self.x + other.x,
 ///             y: self.y + other.y,
 ///         }
@@ -158,9 +158,9 @@ add_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 }
 ///
 /// // Notice that the implementation uses the associated type `Output`.
 /// impl<T: Sub<Output = T>> Sub for Point<T> {
-///     type Output = Point<T>;
+///     type Output = Self;
 ///
-///     fn sub(self, other: Point<T>) -> Point<T> {
+///     fn sub(self, other: Self) -> Self::Output {
 ///         Point {
 ///             x: self.x - other.x,
 ///             y: self.y - other.y,
@@ -280,9 +280,9 @@ sub_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 }
 /// struct Vector { value: Vec<usize> }
 ///
 /// impl Mul<Scalar> for Vector {
-///     type Output = Vector;
+///     type Output = Self;
 ///
-///     fn mul(self, rhs: Scalar) -> Vector {
+///     fn mul(self, rhs: Scalar) -> Self::Output {
 ///         Vector { value: self.value.iter().map(|v| v * rhs.value).collect() }
 ///     }
 /// }
@@ -364,7 +364,7 @@ mul_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 }
 ///     // The division of rational numbers is a closed operation.
 ///     type Output = Self;
 ///
-///     fn div(self, rhs: Self) -> Self {
+///     fn div(self, rhs: Self) -> Self::Output {
 ///         if rhs.nominator == 0 {
 ///             panic!("Cannot divide by zero-valued `Rational`!");
 ///         }
@@ -404,9 +404,9 @@ mul_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 }
 /// struct Vector { value: Vec<f32> }
 ///
 /// impl Div<Scalar> for Vector {
-///     type Output = Vector;
+///     type Output = Self;
 ///
-///     fn div(self, rhs: Scalar) -> Vector {
+///     fn div(self, rhs: Scalar) -> Self::Output {
 ///         Vector { value: self.value.iter().map(|v| v / rhs.value).collect() }
 ///     }
 /// }
@@ -485,9 +485,9 @@ div_impl_float! { f32 f64 }
 /// }
 ///
 /// impl<'a, T> Rem<usize> for SplitSlice<'a, T> {
-///     type Output = SplitSlice<'a, T>;
+///     type Output = Self;
 ///
-///     fn rem(self, modulus: usize) -> Self {
+///     fn rem(self, modulus: usize) -> Self::Output {
 ///         let len = self.slice.len();
 ///         let rem = len % modulus;
 ///         let start = len - rem;
@@ -571,7 +571,7 @@ rem_impl_float! { f32 f64 }
 /// impl Neg for Sign {
 ///     type Output = Sign;
 ///
-///     fn neg(self) -> Sign {
+///     fn neg(self) -> Self::Output {
 ///         match self {
 ///             Sign::Negative => Sign::Positive,
 ///             Sign::Zero => Sign::Zero,
@@ -650,8 +650,8 @@ neg_impl_numeric! { isize i8 i16 i32 i64 i128 f32 f64 }
 /// }
 ///
 /// impl AddAssign for Point {
-///     fn add_assign(&mut self, other: Point) {
-///         *self = Point {
+///     fn add_assign(&mut self, other: Self) {
+///         *self = Self {
 ///             x: self.x + other.x,
 ///             y: self.y + other.y,
 ///         };
@@ -706,8 +706,8 @@ add_assign_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 }
 /// }
 ///
 /// impl SubAssign for Point {
-///     fn sub_assign(&mut self, other: Point) {
-///         *self = Point {
+///     fn sub_assign(&mut self, other: Self) {
+///         *self = Self {
 ///             x: self.x - other.x,
 ///             y: self.y - other.y,
 ///         };