Apply review feedback · qinheping/verify-rust-std@aabd713 (original) (raw)

`@@ -278,7 +278,7 @@ pub macro PartialEq($item:item) {

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`` /// The primary difference to [PartialEq] is the additional requirement for reflexivity. A type

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`` /// that implements [PartialEq] guarantees that for all a, b and c:

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`///

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`` -

/// - symmetric: a == b implies b == a

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`` +

/// - symmetric: a == b implies b == a and a != b implies !(a == b)

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`` /// - transitive: a == b and b == c implies a == c

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`///

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`` /// Eq, which builds on top of [PartialEq] also implies:

`@@ -332,11 +332,9 @@ pub macro PartialEq($item:item) {

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`#[stable(feature = "rust1", since = "1.0.0")]

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`#[rustc_diagnostic_item = "Eq"]

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`pub trait Eq: PartialEq {

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// this method is used solely by #[derive(Eq)] to assert

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`` -

// that every component of a type implements Eq

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// itself. The current deriving infrastructure means doing this

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// assertion without using a method on this trait is nearly

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// impossible.

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// this method is used solely by impl Eq or #[derive(Eq)] to assert that every component of a

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// type implements Eq itself. The current deriving infrastructure means doing this assertion

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// without using a method on this trait is nearly impossible.

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`//

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`// This should never be implemented by hand.

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`#[doc(hidden)]

`@@ -789,11 +787,13 @@ impl<T: Clone> Clone for Reverse {

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`` /// fashion Ord builds on top of [PartialOrd] and adds further properties, such as totality,

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`/// which means all values must be comparable.

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`///

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/// Because of different signatures, Ord cannot be a simple marker trait like Eq. So it can't be

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/// derived automatically when PartialOrd is implemented. The recommended best practice for a

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/// type that manually implements Ord is to implement the equality comparison logic in PartialEq

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/// and implement the ordering comparison logic in Ord. From there one should implement

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/// PartialOrd as Some(self.cmp(other)).

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/// Ord requires that the type also be PartialOrd, PartialEq, and Eq.

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///

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/// Because Ord implies a stronger ordering relationship than [PartialOrd], and both Ord and

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/// [PartialOrd] must agree, you must choose how to implement Ord first. You can choose to

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/// derive it, or implement it manually. If you derive it, you should derive all four traits. If you

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/// implement it manually, you should manually implement all four traits, based on the

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/// implementation of Ord.

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`///

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`` /// Here's an example where you want to define the Character comparison by health and

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`` /// experience only, disregarding the field mana:

`@@ -888,7 +888,7 @@ impl<T: Clone> Clone for Reverse {

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```` /// ```


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`/// use std::cmp::Ordering;

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`///

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``

`-

/// #[derive(Eq, Debug)]

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``

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/// #[derive(Debug)]

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`/// struct Character {

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`/// health: u32,

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`/// experience: u32,

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`@@ -918,6 +918,8 @@ impl<T: Clone> Clone for Reverse<T> {

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`/// }

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`/// }

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`///

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/// impl Eq for Character {}

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///

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`/// let a = Character {

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`/// health: 3,

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`/// experience: 5,

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`@@ -1191,7 +1193,6 @@ pub macro Ord($item:item) {

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```` /// ```

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`/// use std::cmp::Ordering;

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`///

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/// #[derive(Eq)]

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`/// struct Person {

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`/// id: u32,

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`/// name: String,

`@@ -1215,6 +1216,8 @@ pub macro Ord($item:item) {

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`/// self.height == other.height

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`/// }

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`/// }

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///

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/// impl Eq for Person {}

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```` /// ```

````

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`///

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`` /// You may also find it useful to use [partial_cmp] on your type's fields. Here is an example of