25 lines
7.8 KiB
Plaintext
25 lines
7.8 KiB
Plaintext
|
rust
|
|||
|
|
« #rustc 1.90.0 (1159e78c4 2025-09-14)Á˜ø½E—y88àìOg[ -a0f3a77406fcd134Á ÒµÅL ®Ùp,ØnWš÷*�Ó -eed239b623db52f0Á‡ ˜
|
|||
|
|
EquivalentÁ KÁ
|
|||
|
|
equivalentÁ QÁ ³ »
|
|||
|
|
ComparableÁ ³ compareÁ Ð ³ þ 8 8 8 88 88 8 г ×Ý d¸ 4¼
|
|||
|
|
ÝÝ× ¸ D¼ ü¤! l¤
|
|||
|
|
É×× $² S - Ë üôW $• × ,‚ Ý ‰ ‚ � keyÁ" Q ŽÉ ½ d¶ 4º Ž ¶ Dº ä§ D§
|
|||
|
|
í× $° F ) É üöS …Ò†Ò‡Ò LessÁ ˆÒ ‰ÒŠÒ‘ ‹Ò ŒÒ�Ò GreaterÁ ŽÒ +8_�)º[Ä D” ‚ ,� Ž ˆ ‚ ë ± © Ž �õ ˜ g4Ü Û ÒDó …Ò ü Ë ü L I [`Equivalent`] and [`Comparable`] are traits for key comparison in maps.Á M © üQM J These may be used in the implementation of maps where the lookup type `Q`Á üŸ2 / may be different than the stored key type `K`.Á Ò © üÖL I * `Q: Equivalent<K>` checks for equality, similar to the `HashMap<K, V>`Á ü£' $ constraint `K: Borrow<Q>, Q: Eq`.Á üËM J * `Q: Comparable<K>` checks the ordering, similar to the `BTreeMap<K, V>`Á ü™( % constraint `K: Borrow<Q>, Q: Ord`.Á  © üÆO L These traits are not used by the maps in the standard library, but they mayÁ ü–J G add more flexibility in third-party map implementations, especially inÁ üáK H situations where a strict `K: Borrow<Q>` relationship is not available.Á © t± # ExamplesÁ À © <Ä ```Á ´Ì use equivalent::*;Á Üã use std::cmp::Ordering;Á ÿ © üƒ( % pub struct Pair<A, B>(pub A, pub B);Á ¬ © ü°R O impl<'a, A: ?Sized, B: ?Sized, C, D> Equivalent<(C, D)> for Pair<&'a A, &'a B>Á Lƒ whereÁ Ì� A: Equivalent<C>,Á ̧ B: Equivalent<D>,Á ,Á {Á üÇ4 1 fn equivalent(&self, key: &(C, D)) -> bool {Á üüB ? self.0.equivalent(&key.0) && self.1.equivalent(&key.1)Á L¿ }Á ,É }Á Ï © üÓR O impl<'a, A: ?Sized, B: ?Sized, C, D> Comparable<(C, D)> for Pair<&'a A, &'a B>Á L¦ ï Ì° A: Comparable<C>,Á ÌÊ B: Comparable<D>,Á ,ä  üê 5 2 fn compare(&self, key: &(C, D)) -> Ordering {Á ü
|
|||
|
|
* ' match self.0.compare(&key.0) {Á üË
|
|||
|
|
: 7 Ordering::Equal => self.1.compare(&key.1),Á ü† ' $ not_equal => not_equal,Á l®
|
|||
|
|
}Á L¼ × ,Æ è Ì © |Ð fn main() {Á üà = : let key = (String::from("foo"), String::from("bar"));Á üž $ ! let q1 = Pair("foo", "bar");Á üà $ ! let q2 = Pair("boo", "bar");Á üè $ ! let q3 = Pair("foo", "baz");Á �
|
|||
|
|
© ü‘
|
|||
|
|
% " assert!(q1.equivalent(&key));Á ü·
|
|||
|
|
& # assert!(!q2.equivalent(&key));Á üÞ
|
|||
|
|
& # assert!(!q3.equivalent(&key));Á … © ü‰6 3 assert_eq!(q1.compare(&key), Ordering::Equal);Á üÀ5 2 assert_eq!(q2.compare(&key), Ordering::Less);Á üö8 5 assert_eq!(q3.compare(&key), Ordering::Greater);Á ,¯ è <µ ý
|
|||
|
|
˜‚ g� Û Ò£ …Ò ¤Î �œè £üû Ôþ Key equivalence trait.Á ™ © ü�L I This trait allows hash table lookup to be customized. It has one blanketÁ üêN K implementation that uses the regular solution with `Borrow` and `Eq`, justÁ ü¹N K like `HashMap` does, so that you can pass `&str` to lookup into a map withÁ äˆ `String` keys and so on.Á ¥ © t© # ContractÁ ¸ © ü¼> ; The implementor **must** hash like `K`, if it is hashable.Á T… ³ “Þ üû‘ “ÞÝ � üä& ü¡> ; Compare self to `key` and return `true` if they are equal.ÁTç é Ý ò
|
|||
|
|
é Ý$ó ± ù üŽQ Ð ³
|
|||
|
|
|
|||
|
|
“Þ× “ õ ž Ì× Ê ÛÝ× LÕ × 35 9; üô% T÷ × Ý ‚
|
|||
|
|
×Ý$ƒ ±üö. ¼Ï Key ordering trait.Á ç © üëM J This trait allows ordered map lookup to be customized. It has one blanketÁ ü¹O L implementation that uses the regular solution with `Borrow` and `Ord`, justÁ ü‰O L like `BTreeMap` does, so that you can pass `&str` to lookup into a map withÁ äÙ ª T€ ³
|
|||
|
|
|
|||
|
|
á üö— é Ý l— õ ‹ °& °&" #% üä' ü«4 1 Compare self to `key` and return their ordering.Á<ç é Ý Ç ï
|
|||
|
|
é Ý$ð ± ö ü�R Ð ³ ÿ! ” õ Ÿ ì× Ë ¥"L× × (* .0 üö& <ù × Ý Ç �
|
|||
|
|
×Ý$‚ ±<;‚ þ ‚^‚ Ž ‚‚ û ‚G‚ � ‚¢ æ æ ¢ æ ¢ ¯ L6Û±‰”╾ø͘K Ê24¬Š6/U@#v1¿ZtHBå
|
|||
|
|
e7.†RõØ¡4}r ÿï‹ r
|