In Rust, traits are used to define shared behavior for types. The following are commonly used traits for comparing types:
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Eq trait: This trait defines the equality relation between two values of a given type. The Eq trait requires that the type implements the PartialEq trait, which defines the partial equality relation. If two values of a type are equal according to the Eq trait, they must be considered indistinguishable in every way.
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PartialEq trait: This trait defines the partial equality relation between two values of a given type. The PartialEq trait requires that the type implements an eq method that takes another value of the same type as an argument, and returns a bool indicating whether the two values are equal. If two values of a type are equal according to the PartialEq trait, they must be considered indistinguishable for the purposes of the Eq trait as well.
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Ord trait: This trait defines the total order relation between two values of a given type. The Ord trait requires that the type implements the PartialOrd trait, which defines the partial order relation. If two values of a type are compared using the Ord trait, they must be completely ordered in a consistent way.
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PartialOrd trait: This trait defines the partial order relation between two values of a given type. The PartialOrd trait requires that the type implements a partial_cmp method that takes another value of the same type as an argument, and returns an Option indicating the ordering relationship between the two values. If two values of a type are compared using the PartialOrd trait, they must be partially ordered in a consistent way.
These traits are important for comparing types in Rust, and are used extensively in Rust's standard library.