4957 shaares
Nombre de jours écoulés depuis la dernière fuite massive de données touchant plusieurs dizaines de millions de comptes chez les GAFAM :
0 jours
Voilà. Ne faites pas confiance aux GAFAM, ne confiez pas vos données privées à des tiers, ne mettez pas vos données privées sur l'ordinateur d'un autre (on appelle ça "le cloud"). Même les entreprises embauchant les soi-disant meilleurs ingénieurs du monde se font hacker en per-man-ence.
Heureusement ici on ne parle "que" de 235 millions de comptes... lol ou pas...
Je backup le lien, ça peut toujours être utile #WeekendsDansLaBelleFamille
Via Laglib.
Via Ecyseo.
Il y a une autre raison pour préserver l'argent liquide et non des moindres... Se protéger contre les taux négatifs !
Pré-requis pour comprendre :
- L'argent / La monnaie (en France et en Europe) a été totalement privatisée au moment de la ratification du traité de Maastricht (de mémoire c'est 1991-92). Ce faisant, la France - ainsi que tous les pays membres de l'UE - ont perdu le droit d'émettre et surtout de détruire la monnaie. C'est le système bancaire qui s'en charge au moment du crédit. Très rapidement :
- Quand vous empruntez la banque privée fabrique de la monnaie.
- Quand vous remboursez la banque privée détruit le principale qu'elle a fabriqué.
- Dans l'opération, la banque fabrique uniquement les unités monétaires correspondant au principal emprunté, celles correspondant aux intérêts n'existeront jamais dans le système. Il faudra alors que les générations suivantes empruntent plus que les anciennes pour que les anciennes générations puissent rembourser intégralement leurs crédits, et ainsi de suite jusqu'à explosion de cette pyramide de ponzi transgénérationnelle.
- En parallèle les états membres de l'UE ont eu l'obligation de se financer auprès des marchés financiers à des taux supérieurs à l'inflation.
- Plus un état est jugé fiable, plus ses taux d'emprunt sont bas.
- La fiabilité d'un état au sein même de l'euro-zone est relative aux autres états de cette même zone.
- Les marchés financiers spécules activement contre l'EURO (cf. l'état actuel des balances TARGET2 entre les pays de l'euro-zone).
Rentrons dans le vif du sujet :
- Les banques centrales ont émis massivement de la monnaie (c'est l'assouplissement quantitatif ou "quantitative easing" en anglais) pour "refinancer les banques privées" dans l'espoir imbécile que celles-ci transferent cet argent dans l'économie réelle. En réalité une grande partie est partie sur les marchés financiers.
- En parallèle les banques ne souhaitant plus se prêter entre-elles laissèrent cet argent sur leur compte à la BCE car moins risqué que chez les copains, surtout depuis les sub-primes.
- Pour contraindre les banques privées à sortir cet argent des livres de comptes centraux, la BCE a décidé de mettre en place des taux d'intérêts négatifs.
- Or ces taux se sont répercutés aux entreprises qui ont vu leurs frais bancaires exploser (d'abord en Allemagne).
- Comme certains états sont jugés plus fiables que d'autres (encore une fois l'Allemagne), les marchés préfèrent leur prêter de l'argent à des taux négatifs plutôt que prendre le risque de tout perdre en cas d'effondrement (et ça fait 7 ans bientôt 8 que c'est le cas).
Il faut savoir qu'en économie des taux d'intérêts négatifs signifient que le présent est moins certain/fiable que l'avenir, ce qui est débile et n'a aucun sens mais admettons.
Bref, actuellement les taux négatifs ne peuvent pas être appliqués aux particuliers (même si Christine Lagarde y a longuement réfléchi au FMI en imaginant une "taxe argent liquide". En gros, vous payez en liquide, bah c'est le même prix mais + X%, c'est-à-dire plus le pourcentage des taux négatifs [#Magique)](https://antichesse.cakeozolives.com/./add-tag/Magique)_) et donc votre épargne ne se dévalue pas sans cesse lorsqu'elle est déposé à la banque puisque pas de taux négatifs.
D'ailleurs, si les taux négatifs se produisaient, alors le risque de bank-run puis de banqueroute ferait trembler toutes les institutions financières.
Mais imaginez à présent que 100 % de vos liquidités soient piégées dans le système bancaire. Aucun problème pour créer un impôt privé kisapellerio : taux d'intérêts négatifs. Aucun moyen de transformer son argent en autre chose comme du liquide pour les paiements quotidiens et tous nous serions condamnés à voir que chaque mois, les sommes présentes sur nos comptes et nos livrets ne feraient que baisser.
J'ai été un peu longue et sûrement tout aussi confuse à expliquer la situation mais c'est vraiment la mémerde et le système financier est de loin la plus grande meute de prédateurs que nous devons combattre. Heureusement qu'aucun mouvement ne vient se superposer à nos yeux ni nous diviser en mettant en avant nos différences comme la couleur de peau ou le sexe que les gens pensent avoir en opposition à celui qu'ils ont reçu à la naissance... Oh wait ! #Facepalm
L'explication est IN-CROY-ABLE ! #TrancheDeLolEnPerspective
Je résume parce que ça vaut vraiment son pesant de cacahuètes :
Puisque que les mathématiques - enfin les SJW disent mathématiques mais la docteur se limite à ce qu'elle semble comprendre, à savoir addition/soustraction/moyenne hein, on ne parle pas du calcul intégrale, des sommes de Riemann, ni de la théories des compacts bornés fermés/ouverts - bref je disais puisque les mathématiques ont été utilisées pour comptabiliser et améliorer les rendements des plantations esclavagistes (entre-autre), alors les mathématiques sont racistes. Voilà c'est tout.
Par analogie :
- Puisqu'on peut tuer avec un couteau il faut interdire les couteaux.
- Puisqu'on peut violer avec un sex-toys il faut interdire les sex-toys.
La "docteur" en SJW ne fait pas de différence entre un outil et son usage. J'ai envie de lui dire, puisque les internets (#BenjaminBayard) servent à transmettre des propos racistes alors il faut interdire internet ?
J'espère que les gens vont se rendre compte à quel point l'absence de raisonnement et la mise en avant du ressenti est un retour-arrière vers des âges archaïques où les croyances que des êtres imaginaires vivaient dans le ciel et sous la terre régissaient le monde...
Les SJW sont des intégristes religieux qui se voilent autant la face que les prêtes/rabbins/imams/etc ne le font. Aux mieux ils auront un monde où tout sera prétexte à la soumission d'autrui - enfin ceux qui sont "différents d'eux" #DiversitéQuandÇaArrange. Je pense que les SJW sont en train de devenir les religieux intégristes de demain et que nous les laissons faire sans rien dire !
P.S : alors non, je ne mets pas dans le même panier tous les SJW, je sais qu'il y en a un bon nombre qui milite avec intelligence et raison. Mais je vais quand même amalgamer ceux que les 4Chan et autres communautés appellent le peuple aux cheveux bleus. Ceux-là sont dangereux et non seulement il faut s'en méfier mais je pense qu'il faut aussi les combattre.
Depuis Ansible 2.7, à l'ancienne syntaxe :
- name: 'Do something'
file:
src: '{{ item.1.src }}'
dest: '{{ item.1.dest }}'
state: 'link'
with_subelements:
- '{{ MY_VALUES }}'
- 'folders'
- flags:
skip_missing: Trueest ajoutée celle-ci :
- name: 'Do something'
file:
src: '{{ item.1.src }}'
dest: '{{ item.1.dest }}'
state: 'link'
with_items: '{{ MY_VALUES | subelements('folders', skip_missing=True) }}'Je trouve la seconde nettement plus claire !
Outch, la dernière version stable est touchée (1.3.72). Il est recommandé de migrer vers la 1.4.0 aussitôt qu'elle sera publiée.
La criticité est de 8.8/10, avec une faille permettant une élévation de privilèges, ça fait mal.
Edit : je n'avais pas vu mais Kotlin 1.4.0 était déjà sortie. Il semble que le NIST et l'OWASP aient publié l'info qu'une fois la nouvelle version de Kotlin fût corrigée et publiée par JetBrains. C'est très pro !
Comment créer un build reproductible avec Gradle :
tasks.withType(AbstractArchiveTask) {
preserveFileTimestamps = false
reproducibleFileOrder = true
}Rappel : un build reproductible consiste en un processus qui soit capable de fournir le même binaire (à l’octet près) entre deux commandes de build jouées à deux dates différentes. Comme les archives JAR embarques un timestamp qui chronodate le jour et l'heure build, par défaut ça n'est pas possible.
[...] il s’agit de créer un marché paneuropéen des données à caractère personnel qui repose sur un espace sécurisé de confiance pour le partage des données [...]
Le capitalisme pousse à tout transformer en marchandise. Le corps des femmes, les organes des gens, l'enfance de nos enfants et maintenant notre intimité. Tout est négociable, tout est marchandable, tout et achetable, finalement tout est produit et tout action n'est que consommation.
Ce n'est pas le modèle de société que je souhaite mais tant que pour la plupart des gens il existe l'égalité : démocratie = doit d'élire un mec et de lui abandonner tout droit de vote pour ne plus voter les lois nous-mêmes notre société ne changera pas au contraire et s'engouffrera vers la trajectoire des plus grandes puissances financières car ce sont les seules à être en mesure de financer les campagnes électorales des représentants.
L'autre point qui me fait tiquer ici est le single point of failure d'un datawarehouse gigantesque contenant la vie privée de 550 millions d'européens. Mettons tous nos oeufs dans le même panier en cas de hack c'est plus sûr n'est-ce pas ? Spoiler : non...
Et sinon je vous ai déjà parlé du #Frexit et sortir de ce piège à rat néolibérale qu'on appelle Europe ?
Quelques idées pour animer des rétrospectives. Par contre j'ai quand même beaucoup de mal avec le fait qu'il faille "divertir" ou "amuser" des adultes, la plupart du temps des ingénieurs ou des doctorants, pour qu'ils fassent correctement leur travail. Comme s'ils étaient des enfants quelque part. Imaginez un médecin que l'on doive "motiver" à soigner des patients ou à s'améliorer, c'est absurde...
Bref, je rappelle qu'à l'opposé de l'Agilité il y a la Zerocracy qui finalement va sélectionner les personnes qui restent motivées par elles-mêmes. N'est-ce pas ça ce qui conviendrait le mieux aux entreprises plutôt que de perdre de l'argent à payer des gens dont l'objet n'est que de faire travailler les autres qui ont été recrutés mais demeurent improductifs ?
P.S : je m'inscris dans une logique d'entreprise en disant cela (et donc de rentabilité). Ce n'est pas ce en quoi je crois. Dit autrement, une entreprise visant à accroitre sa rentabilité ne devrait pas faire du social, ni même de l'humain. Ce n'est pas la structure pour ça et Amazon a démontré que les méthodes violentes et cruelles étaient les plus efficaces du point de vue du capital.
Via HowTommy
[...] Même un virus dit plus de vérité qu'un journaliste de BFM [...]
La Bajon
Phrase dite en parlant de la privatisation de l’hôpital public par la réduction de ses moyens
S'te punchline est ouffissime ! <3 <3 <3
Ça m'a tellement frappé que je me suis arrêtée de regarder la vidéo pour écrire ce poste. Je repends juste après ><
EDIT : Je viens de me faire la fin de l'épisode. Je crois qu'elle est encore mieux que le début OO ! Un trèèèèèèèèèèèèèèès grand bravo. 7 min à faire tourner.
Attendez... Le réseau social qui encourage les petites filles à se déshabiller et faire des strip-teases face caméra pour des likes et de l’audimat ne respecterait pas la vie privée de ses utilisateurs et contournerait les restrictions de Google censées "protéger la vie privée"...
La surprise est totale ! (눈_눈)
Article mis sous le coude pour tout à l'heure.
Tout est dit ! Et j'adore Kotlin c'est vous dire. Mais je préfère me tirer une balle que de faire du annotation-driven-development avec un java-procedural-spring-singleton-base programming.
Si je disais précédemment que la PF pure était un cancer, alors Spring et ce mode de programmation est un cancer metastasé !
Merci à @Philou qui me comprends et qui m'a offert ce lien.
Je me suis amusée à regarde l'API standard de Rust.
Vous trouverez ci-après, et à titre d'exemple, le contenu du fichier map.rs de Rust (dans sa version 1.43.0) qui contient l'implémentation de la HashMap. J'imagine que vous saurez tout comme moi apprécier ses 3518 lignes de code... Et on veut encore nous vendre de la PF pure en 2020 !? Après 15 ans d'existence de SonarQube qui pète une alerte pour chaque fichier dépassant les 250 lignes de code car on sait qu'à chaque nouvelle hauteur d'écran à scroller, l'immaintenabilité d'un source croît de manière quadratique...
Et dites-vous bien que toute l'API standard est calquée sur ce même anti-modèle.
// ignore-tidy-filelength
use self::Entry::*;
use hashbrown::hash_map as base;
use crate::borrow::Borrow;
use crate::cell::Cell;
use crate::collections::TryReserveError;
use crate::fmt::{self, Debug};
#[allow(deprecated)]
use crate::hash::{BuildHasher, Hash, Hasher, SipHasher13};
use crate::iter::{FromIterator, FusedIterator};
use crate::ops::Index;
use crate::sys;
/// A hash map implemented with quadratic probing and SIMD lookup.
///
/// By default, `HashMap` uses a hashing algorithm selected to provide
/// resistance against HashDoS attacks. The algorithm is randomly seeded, and a
/// reasonable best-effort is made to generate this seed from a high quality,
/// secure source of randomness provided by the host without blocking the
/// program. Because of this, the randomness of the seed depends on the output
/// quality of the system's random number generator when the seed is created.
/// In particular, seeds generated when the system's entropy pool is abnormally
/// low such as during system boot may be of a lower quality.
///
/// The default hashing algorithm is currently SipHash 1-3, though this is
/// subject to change at any point in the future. While its performance is very
/// competitive for medium sized keys, other hashing algorithms will outperform
/// it for small keys such as integers as well as large keys such as long
/// strings, though those algorithms will typically *not* protect against
/// attacks such as HashDoS.
///
/// The hashing algorithm can be replaced on a per-`HashMap` basis using the
/// [`default`], [`with_hasher`], and [`with_capacity_and_hasher`] methods. Many
/// alternative algorithms are available on crates.io, such as the [`fnv`] crate.
///
/// It is required that the keys implement the [`Eq`] and [`Hash`] traits, although
/// this can frequently be achieved by using `#[derive(PartialEq, Eq, Hash)]`.
/// If you implement these yourself, it is important that the following
/// property holds:
///
/// ```text
/// k1 == k2 -> hash(k1) == hash(k2)
/// ```
///
/// In other words, if two keys are equal, their hashes must be equal.
///
/// It is a logic error for a key to be modified in such a way that the key's
/// hash, as determined by the [`Hash`] trait, or its equality, as determined by
/// the [`Eq`] trait, changes while it is in the map. This is normally only
/// possible through [`Cell`], [`RefCell`], global state, I/O, or unsafe code.
///
/// The hash table implementation is a Rust port of Google's [SwissTable].
/// The original C++ version of SwissTable can be found [here], and this
/// [CppCon talk] gives an overview of how the algorithm works.
///
/// [SwissTable]: https://abseil.io/blog/20180927-swisstables
/// [here]: https://github.com/abseil/abseil-cpp/blob/master/absl/container/internal/raw_hash_set.h
/// [CppCon talk]: https://www.youtube.com/watch?v=ncHmEUmJZf4
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// // Type inference lets us omit an explicit type signature (which
/// // would be `HashMap<String, String>` in this example).
/// let mut book_reviews = HashMap::new();
///
/// // Review some books.
/// book_reviews.insert(
/// "Adventures of Huckleberry Finn".to_string(),
/// "My favorite book.".to_string(),
/// );
/// book_reviews.insert(
/// "Grimms' Fairy Tales".to_string(),
/// "Masterpiece.".to_string(),
/// );
/// book_reviews.insert(
/// "Pride and Prejudice".to_string(),
/// "Very enjoyable.".to_string(),
/// );
/// book_reviews.insert(
/// "The Adventures of Sherlock Holmes".to_string(),
/// "Eye lyked it alot.".to_string(),
/// );
///
/// // Check for a specific one.
/// // When collections store owned values (String), they can still be
/// // queried using references (&str).
/// if !book_reviews.contains_key("Les Misérables") {
/// println!("We've got {} reviews, but Les Misérables ain't one.",
/// book_reviews.len());
/// }
///
/// // oops, this review has a lot of spelling mistakes, let's delete it.
/// book_reviews.remove("The Adventures of Sherlock Holmes");
///
/// // Look up the values associated with some keys.
/// let to_find = ["Pride and Prejudice", "Alice's Adventure in Wonderland"];
/// for &book in &to_find {
/// match book_reviews.get(book) {
/// Some(review) => println!("{}: {}", book, review),
/// None => println!("{} is unreviewed.", book)
/// }
/// }
///
/// // Look up the value for a key (will panic if the key is not found).
/// println!("Review for Jane: {}", book_reviews["Pride and Prejudice"]);
///
/// // Iterate over everything.
/// for (book, review) in &book_reviews {
/// println!("{}: \"{}\"", book, review);
/// }
/// ```
///
/// `HashMap` also implements an [`Entry API`](#method.entry), which allows
/// for more complex methods of getting, setting, updating and removing keys and
/// their values:
///
/// ```
/// use std::collections::HashMap;
///
/// // type inference lets us omit an explicit type signature (which
/// // would be `HashMap<&str, u8>` in this example).
/// let mut player_stats = HashMap::new();
///
/// fn random_stat_buff() -> u8 {
/// // could actually return some random value here - let's just return
/// // some fixed value for now
/// 42
/// }
///
/// // insert a key only if it doesn't already exist
/// player_stats.entry("health").or_insert(100);
///
/// // insert a key using a function that provides a new value only if it
/// // doesn't already exist
/// player_stats.entry("defence").or_insert_with(random_stat_buff);
///
/// // update a key, guarding against the key possibly not being set
/// let stat = player_stats.entry("attack").or_insert(100);
/// *stat += random_stat_buff();
/// ```
///
/// The easiest way to use `HashMap` with a custom key type is to derive [`Eq`] and [`Hash`].
/// We must also derive [`PartialEq`].
///
/// [`Eq`]: ../../std/cmp/trait.Eq.html
/// [`Hash`]: ../../std/hash/trait.Hash.html
/// [`PartialEq`]: ../../std/cmp/trait.PartialEq.html
/// [`RefCell`]: ../../std/cell/struct.RefCell.html
/// [`Cell`]: ../../std/cell/struct.Cell.html
/// [`default`]: #method.default
/// [`with_hasher`]: #method.with_hasher
/// [`with_capacity_and_hasher`]: #method.with_capacity_and_hasher
/// [`fnv`]: https://crates.io/crates/fnv
///
/// ```
/// use std::collections::HashMap;
///
/// #[derive(Hash, Eq, PartialEq, Debug)]
/// struct Viking {
/// name: String,
/// country: String,
/// }
///
/// impl Viking {
/// /// Creates a new Viking.
/// fn new(name: &str, country: &str) -> Viking {
/// Viking { name: name.to_string(), country: country.to_string() }
/// }
/// }
///
/// // Use a HashMap to store the vikings' health points.
/// let mut vikings = HashMap::new();
///
/// vikings.insert(Viking::new("Einar", "Norway"), 25);
/// vikings.insert(Viking::new("Olaf", "Denmark"), 24);
/// vikings.insert(Viking::new("Harald", "Iceland"), 12);
///
/// // Use derived implementation to print the status of the vikings.
/// for (viking, health) in &vikings {
/// println!("{:?} has {} hp", viking, health);
/// }
/// ```
///
/// A `HashMap` with fixed list of elements can be initialized from an array:
///
/// ```
/// use std::collections::HashMap;
///
/// let timber_resources: HashMap<&str, i32> = [("Norway", 100), ("Denmark", 50), ("Iceland", 10)]
/// .iter().cloned().collect();
/// // use the values stored in map
/// ```
#[derive(Clone)]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct HashMap<K, V, S = RandomState> {
base: base::HashMap<K, V, S>,
}
impl<K, V> HashMap<K, V, RandomState> {
/// Creates an empty `HashMap`.
///
/// The hash map is initially created with a capacity of 0, so it will not allocate until it
/// is first inserted into.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// let mut map: HashMap<&str, i32> = HashMap::new();
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn new() -> HashMap<K, V, RandomState> {
Default::default()
}
/// Creates an empty `HashMap` with the specified capacity.
///
/// The hash map will be able to hold at least `capacity` elements without
/// reallocating. If `capacity` is 0, the hash map will not allocate.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// let mut map: HashMap<&str, i32> = HashMap::with_capacity(10);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn with_capacity(capacity: usize) -> HashMap<K, V, RandomState> {
HashMap::with_capacity_and_hasher(capacity, Default::default())
}
}
impl<K, V, S> HashMap<K, V, S> {
/// Creates an empty `HashMap` which will use the given hash builder to hash
/// keys.
///
/// The created map has the default initial capacity.
///
/// Warning: `hash_builder` is normally randomly generated, and
/// is designed to allow HashMaps to be resistant to attacks that
/// cause many collisions and very poor performance. Setting it
/// manually using this function can expose a DoS attack vector.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// use std::collections::hash_map::RandomState;
///
/// let s = RandomState::new();
/// let mut map = HashMap::with_hasher(s);
/// map.insert(1, 2);
/// ```
#[inline]
#[stable(feature = "hashmap_build_hasher", since = "1.7.0")]
pub fn with_hasher(hash_builder: S) -> HashMap<K, V, S> {
HashMap { base: base::HashMap::with_hasher(hash_builder) }
}
/// Creates an empty `HashMap` with the specified capacity, using `hash_builder`
/// to hash the keys.
///
/// The hash map will be able to hold at least `capacity` elements without
/// reallocating. If `capacity` is 0, the hash map will not allocate.
///
/// Warning: `hash_builder` is normally randomly generated, and
/// is designed to allow HashMaps to be resistant to attacks that
/// cause many collisions and very poor performance. Setting it
/// manually using this function can expose a DoS attack vector.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// use std::collections::hash_map::RandomState;
///
/// let s = RandomState::new();
/// let mut map = HashMap::with_capacity_and_hasher(10, s);
/// map.insert(1, 2);
/// ```
#[inline]
#[stable(feature = "hashmap_build_hasher", since = "1.7.0")]
pub fn with_capacity_and_hasher(capacity: usize, hash_builder: S) -> HashMap<K, V, S> {
HashMap { base: base::HashMap::with_capacity_and_hasher(capacity, hash_builder) }
}
/// Returns the number of elements the map can hold without reallocating.
///
/// This number is a lower bound; the `HashMap<K, V>` might be able to hold
/// more, but is guaranteed to be able to hold at least this many.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// let map: HashMap<i32, i32> = HashMap::with_capacity(100);
/// assert!(map.capacity() >= 100);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn capacity(&self) -> usize {
self.base.capacity()
}
/// An iterator visiting all keys in arbitrary order.
/// The iterator element type is `&'a K`.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert("a", 1);
/// map.insert("b", 2);
/// map.insert("c", 3);
///
/// for key in map.keys() {
/// println!("{}", key);
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn keys(&self) -> Keys<'_, K, V> {
Keys { inner: self.iter() }
}
/// An iterator visiting all values in arbitrary order.
/// The iterator element type is `&'a V`.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert("a", 1);
/// map.insert("b", 2);
/// map.insert("c", 3);
///
/// for val in map.values() {
/// println!("{}", val);
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn values(&self) -> Values<'_, K, V> {
Values { inner: self.iter() }
}
/// An iterator visiting all values mutably in arbitrary order.
/// The iterator element type is `&'a mut V`.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map = HashMap::new();
///
/// map.insert("a", 1);
/// map.insert("b", 2);
/// map.insert("c", 3);
///
/// for val in map.values_mut() {
/// *val = *val + 10;
/// }
///
/// for val in map.values() {
/// println!("{}", val);
/// }
/// ```
#[stable(feature = "map_values_mut", since = "1.10.0")]
pub fn values_mut(&mut self) -> ValuesMut<'_, K, V> {
ValuesMut { inner: self.iter_mut() }
}
/// An iterator visiting all key-value pairs in arbitrary order.
/// The iterator element type is `(&'a K, &'a V)`.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert("a", 1);
/// map.insert("b", 2);
/// map.insert("c", 3);
///
/// for (key, val) in map.iter() {
/// println!("key: {} val: {}", key, val);
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn iter(&self) -> Iter<'_, K, V> {
Iter { base: self.base.iter() }
}
/// An iterator visiting all key-value pairs in arbitrary order,
/// with mutable references to the values.
/// The iterator element type is `(&'a K, &'a mut V)`.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert("a", 1);
/// map.insert("b", 2);
/// map.insert("c", 3);
///
/// // Update all values
/// for (_, val) in map.iter_mut() {
/// *val *= 2;
/// }
///
/// for (key, val) in &map {
/// println!("key: {} val: {}", key, val);
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn iter_mut(&mut self) -> IterMut<'_, K, V> {
IterMut { base: self.base.iter_mut() }
}
/// Returns the number of elements in the map.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut a = HashMap::new();
/// assert_eq!(a.len(), 0);
/// a.insert(1, "a");
/// assert_eq!(a.len(), 1);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn len(&self) -> usize {
self.base.len()
}
/// Returns `true` if the map contains no elements.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut a = HashMap::new();
/// assert!(a.is_empty());
/// a.insert(1, "a");
/// assert!(!a.is_empty());
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn is_empty(&self) -> bool {
self.base.is_empty()
}
/// Clears the map, returning all key-value pairs as an iterator. Keeps the
/// allocated memory for reuse.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut a = HashMap::new();
/// a.insert(1, "a");
/// a.insert(2, "b");
///
/// for (k, v) in a.drain().take(1) {
/// assert!(k == 1 || k == 2);
/// assert!(v == "a" || v == "b");
/// }
///
/// assert!(a.is_empty());
/// ```
#[inline]
#[stable(feature = "drain", since = "1.6.0")]
pub fn drain(&mut self) -> Drain<'_, K, V> {
Drain { base: self.base.drain() }
}
/// Clears the map, removing all key-value pairs. Keeps the allocated memory
/// for reuse.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut a = HashMap::new();
/// a.insert(1, "a");
/// a.clear();
/// assert!(a.is_empty());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn clear(&mut self) {
self.base.clear();
}
/// Returns a reference to the map's [`BuildHasher`].
///
/// [`BuildHasher`]: ../../std/hash/trait.BuildHasher.html
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// use std::collections::hash_map::RandomState;
///
/// let hasher = RandomState::new();
/// let map: HashMap<i32, i32> = HashMap::with_hasher(hasher);
/// let hasher: &RandomState = map.hasher();
/// ```
#[inline]
#[stable(feature = "hashmap_public_hasher", since = "1.9.0")]
pub fn hasher(&self) -> &S {
self.base.hasher()
}
}
impl<K, V, S> HashMap<K, V, S>
where
K: Eq + Hash,
S: BuildHasher,
{
/// Reserves capacity for at least `additional` more elements to be inserted
/// in the `HashMap`. The collection may reserve more space to avoid
/// frequent reallocations.
///
/// # Panics
///
/// Panics if the new allocation size overflows [`usize`].
///
/// [`usize`]: ../../std/primitive.usize.html
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// let mut map: HashMap<&str, i32> = HashMap::new();
/// map.reserve(10);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn reserve(&mut self, additional: usize) {
self.base.reserve(additional)
}
/// Tries to reserve capacity for at least `additional` more elements to be inserted
/// in the given `HashMap<K,V>`. The collection may reserve more space to avoid
/// frequent reallocations.
///
/// # Errors
///
/// If the capacity overflows, or the allocator reports a failure, then an error
/// is returned.
///
/// # Examples
///
/// ```
/// #![feature(try_reserve)]
/// use std::collections::HashMap;
/// let mut map: HashMap<&str, isize> = HashMap::new();
/// map.try_reserve(10).expect("why is the test harness OOMing on 10 bytes?");
/// ```
#[inline]
#[unstable(feature = "try_reserve", reason = "new API", issue = "48043")]
pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> {
self.base.try_reserve(additional).map_err(map_collection_alloc_err)
}
/// Shrinks the capacity of the map as much as possible. It will drop
/// down as much as possible while maintaining the internal rules
/// and possibly leaving some space in accordance with the resize policy.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map: HashMap<i32, i32> = HashMap::with_capacity(100);
/// map.insert(1, 2);
/// map.insert(3, 4);
/// assert!(map.capacity() >= 100);
/// map.shrink_to_fit();
/// assert!(map.capacity() >= 2);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn shrink_to_fit(&mut self) {
self.base.shrink_to_fit();
}
/// Shrinks the capacity of the map with a lower limit. It will drop
/// down no lower than the supplied limit while maintaining the internal rules
/// and possibly leaving some space in accordance with the resize policy.
///
/// Panics if the current capacity is smaller than the supplied
/// minimum capacity.
///
/// # Examples
///
/// ```
/// #![feature(shrink_to)]
/// use std::collections::HashMap;
///
/// let mut map: HashMap<i32, i32> = HashMap::with_capacity(100);
/// map.insert(1, 2);
/// map.insert(3, 4);
/// assert!(map.capacity() >= 100);
/// map.shrink_to(10);
/// assert!(map.capacity() >= 10);
/// map.shrink_to(0);
/// assert!(map.capacity() >= 2);
/// ```
#[inline]
#[unstable(feature = "shrink_to", reason = "new API", issue = "56431")]
pub fn shrink_to(&mut self, min_capacity: usize) {
assert!(self.capacity() >= min_capacity, "Tried to shrink to a larger capacity");
self.base.shrink_to(min_capacity);
}
/// Gets the given key's corresponding entry in the map for in-place manipulation.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut letters = HashMap::new();
///
/// for ch in "a short treatise on fungi".chars() {
/// let counter = letters.entry(ch).or_insert(0);
/// *counter += 1;
/// }
///
/// assert_eq!(letters[&'s'], 2);
/// assert_eq!(letters[&'t'], 3);
/// assert_eq!(letters[&'u'], 1);
/// assert_eq!(letters.get(&'y'), None);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn entry(&mut self, key: K) -> Entry<'_, K, V> {
map_entry(self.base.rustc_entry(key))
}
/// Returns a reference to the value corresponding to the key.
///
/// The key may be any borrowed form of the map's key type, but
/// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
/// the key type.
///
/// [`Eq`]: ../../std/cmp/trait.Eq.html
/// [`Hash`]: ../../std/hash/trait.Hash.html
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert(1, "a");
/// assert_eq!(map.get(&1), Some(&"a"));
/// assert_eq!(map.get(&2), None);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn get<Q: ?Sized>(&self, k: &Q) -> Option<&V>
where
K: Borrow<Q>,
Q: Hash + Eq,
{
self.base.get(k)
}
/// Returns the key-value pair corresponding to the supplied key.
///
/// The supplied key may be any borrowed form of the map's key type, but
/// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
/// the key type.
///
/// [`Eq`]: ../../std/cmp/trait.Eq.html
/// [`Hash`]: ../../std/hash/trait.Hash.html
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert(1, "a");
/// assert_eq!(map.get_key_value(&1), Some((&1, &"a")));
/// assert_eq!(map.get_key_value(&2), None);
/// ```
#[stable(feature = "map_get_key_value", since = "1.40.0")]
#[inline]
pub fn get_key_value<Q: ?Sized>(&self, k: &Q) -> Option<(&K, &V)>
where
K: Borrow<Q>,
Q: Hash + Eq,
{
self.base.get_key_value(k)
}
/// Returns `true` if the map contains a value for the specified key.
///
/// The key may be any borrowed form of the map's key type, but
/// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
/// the key type.
///
/// [`Eq`]: ../../std/cmp/trait.Eq.html
/// [`Hash`]: ../../std/hash/trait.Hash.html
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert(1, "a");
/// assert_eq!(map.contains_key(&1), true);
/// assert_eq!(map.contains_key(&2), false);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn contains_key<Q: ?Sized>(&self, k: &Q) -> bool
where
K: Borrow<Q>,
Q: Hash + Eq,
{
self.base.contains_key(k)
}
/// Returns a mutable reference to the value corresponding to the key.
///
/// The key may be any borrowed form of the map's key type, but
/// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
/// the key type.
///
/// [`Eq`]: ../../std/cmp/trait.Eq.html
/// [`Hash`]: ../../std/hash/trait.Hash.html
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert(1, "a");
/// if let Some(x) = map.get_mut(&1) {
/// *x = "b";
/// }
/// assert_eq!(map[&1], "b");
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn get_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut V>
where
K: Borrow<Q>,
Q: Hash + Eq,
{
self.base.get_mut(k)
}
/// Inserts a key-value pair into the map.
///
/// If the map did not have this key present, [`None`] is returned.
///
/// If the map did have this key present, the value is updated, and the old
/// value is returned. The key is not updated, though; this matters for
/// types that can be `==` without being identical. See the [module-level
/// documentation] for more.
///
/// [`None`]: ../../std/option/enum.Option.html#variant.None
/// [module-level documentation]: index.html#insert-and-complex-keys
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map = HashMap::new();
/// assert_eq!(map.insert(37, "a"), None);
/// assert_eq!(map.is_empty(), false);
///
/// map.insert(37, "b");
/// assert_eq!(map.insert(37, "c"), Some("b"));
/// assert_eq!(map[&37], "c");
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn insert(&mut self, k: K, v: V) -> Option<V> {
self.base.insert(k, v)
}
/// Removes a key from the map, returning the value at the key if the key
/// was previously in the map.
///
/// The key may be any borrowed form of the map's key type, but
/// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
/// the key type.
///
/// [`Eq`]: ../../std/cmp/trait.Eq.html
/// [`Hash`]: ../../std/hash/trait.Hash.html
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert(1, "a");
/// assert_eq!(map.remove(&1), Some("a"));
/// assert_eq!(map.remove(&1), None);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn remove<Q: ?Sized>(&mut self, k: &Q) -> Option<V>
where
K: Borrow<Q>,
Q: Hash + Eq,
{
self.base.remove(k)
}
/// Removes a key from the map, returning the stored key and value if the
/// key was previously in the map.
///
/// The key may be any borrowed form of the map's key type, but
/// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
/// the key type.
///
/// [`Eq`]: ../../std/cmp/trait.Eq.html
/// [`Hash`]: ../../std/hash/trait.Hash.html
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// # fn main() {
/// let mut map = HashMap::new();
/// map.insert(1, "a");
/// assert_eq!(map.remove_entry(&1), Some((1, "a")));
/// assert_eq!(map.remove(&1), None);
/// # }
/// ```
#[stable(feature = "hash_map_remove_entry", since = "1.27.0")]
#[inline]
pub fn remove_entry<Q: ?Sized>(&mut self, k: &Q) -> Option<(K, V)>
where
K: Borrow<Q>,
Q: Hash + Eq,
{
self.base.remove_entry(k)
}
/// Retains only the elements specified by the predicate.
///
/// In other words, remove all pairs `(k, v)` such that `f(&k,&mut v)` returns `false`.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map: HashMap<i32, i32> = (0..8).map(|x|(x, x*10)).collect();
/// map.retain(|&k, _| k % 2 == 0);
/// assert_eq!(map.len(), 4);
/// ```
#[stable(feature = "retain_hash_collection", since = "1.18.0")]
#[inline]
pub fn retain<F>(&mut self, f: F)
where
F: FnMut(&K, &mut V) -> bool,
{
self.base.retain(f)
}
}
impl<K, V, S> HashMap<K, V, S>
where
S: BuildHasher,
{
/// Creates a raw entry builder for the HashMap.
///
/// Raw entries provide the lowest level of control for searching and
/// manipulating a map. They must be manually initialized with a hash and
/// then manually searched. After this, insertions into a vacant entry
/// still require an owned key to be provided.
///
/// Raw entries are useful for such exotic situations as:
///
/// * Hash memoization
/// * Deferring the creation of an owned key until it is known to be required
/// * Using a search key that doesn't work with the Borrow trait
/// * Using custom comparison logic without newtype wrappers
///
/// Because raw entries provide much more low-level control, it's much easier
/// to put the HashMap into an inconsistent state which, while memory-safe,
/// will cause the map to produce seemingly random results. Higher-level and
/// more foolproof APIs like `entry` should be preferred when possible.
///
/// In particular, the hash used to initialized the raw entry must still be
/// consistent with the hash of the key that is ultimately stored in the entry.
/// This is because implementations of HashMap may need to recompute hashes
/// when resizing, at which point only the keys are available.
///
/// Raw entries give mutable access to the keys. This must not be used
/// to modify how the key would compare or hash, as the map will not re-evaluate
/// where the key should go, meaning the keys may become "lost" if their
/// location does not reflect their state. For instance, if you change a key
/// so that the map now contains keys which compare equal, search may start
/// acting erratically, with two keys randomly masking each other. Implementations
/// are free to assume this doesn't happen (within the limits of memory-safety).
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn raw_entry_mut(&mut self) -> RawEntryBuilderMut<'_, K, V, S> {
RawEntryBuilderMut { map: self }
}
/// Creates a raw immutable entry builder for the HashMap.
///
/// Raw entries provide the lowest level of control for searching and
/// manipulating a map. They must be manually initialized with a hash and
/// then manually searched.
///
/// This is useful for
/// * Hash memoization
/// * Using a search key that doesn't work with the Borrow trait
/// * Using custom comparison logic without newtype wrappers
///
/// Unless you are in such a situation, higher-level and more foolproof APIs like
/// `get` should be preferred.
///
/// Immutable raw entries have very limited use; you might instead want `raw_entry_mut`.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn raw_entry(&self) -> RawEntryBuilder<'_, K, V, S> {
RawEntryBuilder { map: self }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V, S> PartialEq for HashMap<K, V, S>
where
K: Eq + Hash,
V: PartialEq,
S: BuildHasher,
{
fn eq(&self, other: &HashMap<K, V, S>) -> bool {
if self.len() != other.len() {
return false;
}
self.iter().all(|(key, value)| other.get(key).map_or(false, |v| *value == *v))
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V, S> Eq for HashMap<K, V, S>
where
K: Eq + Hash,
V: Eq,
S: BuildHasher,
{
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V, S> Debug for HashMap<K, V, S>
where
K: Debug,
V: Debug,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_map().entries(self.iter()).finish()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V, S> Default for HashMap<K, V, S>
where
S: Default,
{
/// Creates an empty `HashMap<K, V, S>`, with the `Default` value for the hasher.
#[inline]
fn default() -> HashMap<K, V, S> {
HashMap::with_hasher(Default::default())
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, Q: ?Sized, V, S> Index<&Q> for HashMap<K, V, S>
where
K: Eq + Hash + Borrow<Q>,
Q: Eq + Hash,
S: BuildHasher,
{
type Output = V;
/// Returns a reference to the value corresponding to the supplied key.
///
/// # Panics
///
/// Panics if the key is not present in the `HashMap`.
#[inline]
fn index(&self, key: &Q) -> &V {
self.get(key).expect("no entry found for key")
}
}
/// An iterator over the entries of a `HashMap`.
///
/// This `struct` is created by the [`iter`] method on [`HashMap`]. See its
/// documentation for more.
///
/// [`iter`]: struct.HashMap.html#method.iter
/// [`HashMap`]: struct.HashMap.html
#[stable(feature = "rust1", since = "1.0.0")]
pub struct Iter<'a, K: 'a, V: 'a> {
base: base::Iter<'a, K, V>,
}
// FIXME(#26925) Remove in favor of `#[derive(Clone)]`
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V> Clone for Iter<'_, K, V> {
#[inline]
fn clone(&self) -> Self {
Iter { base: self.base.clone() }
}
}
#[stable(feature = "std_debug", since = "1.16.0")]
impl<K: Debug, V: Debug> fmt::Debug for Iter<'_, K, V> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.clone()).finish()
}
}
/// A mutable iterator over the entries of a `HashMap`.
///
/// This `struct` is created by the [`iter_mut`] method on [`HashMap`]. See its
/// documentation for more.
///
/// [`iter_mut`]: struct.HashMap.html#method.iter_mut
/// [`HashMap`]: struct.HashMap.html
#[stable(feature = "rust1", since = "1.0.0")]
pub struct IterMut<'a, K: 'a, V: 'a> {
base: base::IterMut<'a, K, V>,
}
impl<'a, K, V> IterMut<'a, K, V> {
/// Returns a iterator of references over the remaining items.
#[inline]
pub(super) fn iter(&self) -> Iter<'_, K, V> {
Iter { base: self.base.rustc_iter() }
}
}
/// An owning iterator over the entries of a `HashMap`.
///
/// This `struct` is created by the [`into_iter`] method on [`HashMap`]
/// (provided by the `IntoIterator` trait). See its documentation for more.
///
/// [`into_iter`]: struct.HashMap.html#method.into_iter
/// [`HashMap`]: struct.HashMap.html
#[stable(feature = "rust1", since = "1.0.0")]
pub struct IntoIter<K, V> {
base: base::IntoIter<K, V>,
}
impl<K, V> IntoIter<K, V> {
/// Returns a iterator of references over the remaining items.
#[inline]
pub(super) fn iter(&self) -> Iter<'_, K, V> {
Iter { base: self.base.rustc_iter() }
}
}
/// An iterator over the keys of a `HashMap`.
///
/// This `struct` is created by the [`keys`] method on [`HashMap`]. See its
/// documentation for more.
///
/// [`keys`]: struct.HashMap.html#method.keys
/// [`HashMap`]: struct.HashMap.html
#[stable(feature = "rust1", since = "1.0.0")]
pub struct Keys<'a, K: 'a, V: 'a> {
inner: Iter<'a, K, V>,
}
// FIXME(#26925) Remove in favor of `#[derive(Clone)]`
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V> Clone for Keys<'_, K, V> {
#[inline]
fn clone(&self) -> Self {
Keys { inner: self.inner.clone() }
}
}
#[stable(feature = "std_debug", since = "1.16.0")]
impl<K: Debug, V> fmt::Debug for Keys<'_, K, V> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.clone()).finish()
}
}
/// An iterator over the values of a `HashMap`.
///
/// This `struct` is created by the [`values`] method on [`HashMap`]. See its
/// documentation for more.
///
/// [`values`]: struct.HashMap.html#method.values
/// [`HashMap`]: struct.HashMap.html
#[stable(feature = "rust1", since = "1.0.0")]
pub struct Values<'a, K: 'a, V: 'a> {
inner: Iter<'a, K, V>,
}
// FIXME(#26925) Remove in favor of `#[derive(Clone)]`
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V> Clone for Values<'_, K, V> {
#[inline]
fn clone(&self) -> Self {
Values { inner: self.inner.clone() }
}
}
#[stable(feature = "std_debug", since = "1.16.0")]
impl<K, V: Debug> fmt::Debug for Values<'_, K, V> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.clone()).finish()
}
}
/// A draining iterator over the entries of a `HashMap`.
///
/// This `struct` is created by the [`drain`] method on [`HashMap`]. See its
/// documentation for more.
///
/// [`drain`]: struct.HashMap.html#method.drain
/// [`HashMap`]: struct.HashMap.html
#[stable(feature = "drain", since = "1.6.0")]
pub struct Drain<'a, K: 'a, V: 'a> {
base: base::Drain<'a, K, V>,
}
impl<'a, K, V> Drain<'a, K, V> {
/// Returns a iterator of references over the remaining items.
#[inline]
pub(super) fn iter(&self) -> Iter<'_, K, V> {
Iter { base: self.base.rustc_iter() }
}
}
/// A mutable iterator over the values of a `HashMap`.
///
/// This `struct` is created by the [`values_mut`] method on [`HashMap`]. See its
/// documentation for more.
///
/// [`values_mut`]: struct.HashMap.html#method.values_mut
/// [`HashMap`]: struct.HashMap.html
#[stable(feature = "map_values_mut", since = "1.10.0")]
pub struct ValuesMut<'a, K: 'a, V: 'a> {
inner: IterMut<'a, K, V>,
}
/// A builder for computing where in a HashMap a key-value pair would be stored.
///
/// See the [`HashMap::raw_entry_mut`] docs for usage examples.
///
/// [`HashMap::raw_entry_mut`]: struct.HashMap.html#method.raw_entry_mut
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub struct RawEntryBuilderMut<'a, K: 'a, V: 'a, S: 'a> {
map: &'a mut HashMap<K, V, S>,
}
/// A view into a single entry in a map, which may either be vacant or occupied.
///
/// This is a lower-level version of [`Entry`].
///
/// This `enum` is constructed through the [`raw_entry_mut`] method on [`HashMap`],
/// then calling one of the methods of that [`RawEntryBuilderMut`].
///
/// [`HashMap`]: struct.HashMap.html
/// [`Entry`]: enum.Entry.html
/// [`raw_entry_mut`]: struct.HashMap.html#method.raw_entry_mut
/// [`RawEntryBuilderMut`]: struct.RawEntryBuilderMut.html
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub enum RawEntryMut<'a, K: 'a, V: 'a, S: 'a> {
/// An occupied entry.
Occupied(RawOccupiedEntryMut<'a, K, V>),
/// A vacant entry.
Vacant(RawVacantEntryMut<'a, K, V, S>),
}
/// A view into an occupied entry in a `HashMap`.
/// It is part of the [`RawEntryMut`] enum.
///
/// [`RawEntryMut`]: enum.RawEntryMut.html
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub struct RawOccupiedEntryMut<'a, K: 'a, V: 'a> {
base: base::RawOccupiedEntryMut<'a, K, V>,
}
/// A view into a vacant entry in a `HashMap`.
/// It is part of the [`RawEntryMut`] enum.
///
/// [`RawEntryMut`]: enum.RawEntryMut.html
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub struct RawVacantEntryMut<'a, K: 'a, V: 'a, S: 'a> {
base: base::RawVacantEntryMut<'a, K, V, S>,
}
/// A builder for computing where in a HashMap a key-value pair would be stored.
///
/// See the [`HashMap::raw_entry`] docs for usage examples.
///
/// [`HashMap::raw_entry`]: struct.HashMap.html#method.raw_entry
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub struct RawEntryBuilder<'a, K: 'a, V: 'a, S: 'a> {
map: &'a HashMap<K, V, S>,
}
impl<'a, K, V, S> RawEntryBuilderMut<'a, K, V, S>
where
S: BuildHasher,
{
/// Creates a `RawEntryMut` from the given key.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn from_key<Q: ?Sized>(self, k: &Q) -> RawEntryMut<'a, K, V, S>
where
K: Borrow<Q>,
Q: Hash + Eq,
{
map_raw_entry(self.map.base.raw_entry_mut().from_key(k))
}
/// Creates a `RawEntryMut` from the given key and its hash.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn from_key_hashed_nocheck<Q: ?Sized>(self, hash: u64, k: &Q) -> RawEntryMut<'a, K, V, S>
where
K: Borrow<Q>,
Q: Eq,
{
map_raw_entry(self.map.base.raw_entry_mut().from_key_hashed_nocheck(hash, k))
}
/// Creates a `RawEntryMut` from the given hash.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn from_hash<F>(self, hash: u64, is_match: F) -> RawEntryMut<'a, K, V, S>
where
for<'b> F: FnMut(&'b K) -> bool,
{
map_raw_entry(self.map.base.raw_entry_mut().from_hash(hash, is_match))
}
}
impl<'a, K, V, S> RawEntryBuilder<'a, K, V, S>
where
S: BuildHasher,
{
/// Access an entry by key.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn from_key<Q: ?Sized>(self, k: &Q) -> Option<(&'a K, &'a V)>
where
K: Borrow<Q>,
Q: Hash + Eq,
{
self.map.base.raw_entry().from_key(k)
}
/// Access an entry by a key and its hash.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn from_key_hashed_nocheck<Q: ?Sized>(self, hash: u64, k: &Q) -> Option<(&'a K, &'a V)>
where
K: Borrow<Q>,
Q: Hash + Eq,
{
self.map.base.raw_entry().from_key_hashed_nocheck(hash, k)
}
/// Access an entry by hash.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn from_hash<F>(self, hash: u64, is_match: F) -> Option<(&'a K, &'a V)>
where
F: FnMut(&K) -> bool,
{
self.map.base.raw_entry().from_hash(hash, is_match)
}
}
impl<'a, K, V, S> RawEntryMut<'a, K, V, S> {
/// Ensures a value is in the entry by inserting the default if empty, and returns
/// mutable references to the key and value in the entry.
///
/// # Examples
///
/// ```
/// #![feature(hash_raw_entry)]
/// use std::collections::HashMap;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
///
/// map.raw_entry_mut().from_key("poneyland").or_insert("poneyland", 3);
/// assert_eq!(map["poneyland"], 3);
///
/// *map.raw_entry_mut().from_key("poneyland").or_insert("poneyland", 10).1 *= 2;
/// assert_eq!(map["poneyland"], 6);
/// ```
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn or_insert(self, default_key: K, default_val: V) -> (&'a mut K, &'a mut V)
where
K: Hash,
S: BuildHasher,
{
match self {
RawEntryMut::Occupied(entry) => entry.into_key_value(),
RawEntryMut::Vacant(entry) => entry.insert(default_key, default_val),
}
}
/// Ensures a value is in the entry by inserting the result of the default function if empty,
/// and returns mutable references to the key and value in the entry.
///
/// # Examples
///
/// ```
/// #![feature(hash_raw_entry)]
/// use std::collections::HashMap;
///
/// let mut map: HashMap<&str, String> = HashMap::new();
///
/// map.raw_entry_mut().from_key("poneyland").or_insert_with(|| {
/// ("poneyland", "hoho".to_string())
/// });
///
/// assert_eq!(map["poneyland"], "hoho".to_string());
/// ```
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn or_insert_with<F>(self, default: F) -> (&'a mut K, &'a mut V)
where
F: FnOnce() -> (K, V),
K: Hash,
S: BuildHasher,
{
match self {
RawEntryMut::Occupied(entry) => entry.into_key_value(),
RawEntryMut::Vacant(entry) => {
let (k, v) = default();
entry.insert(k, v)
}
}
}
/// Provides in-place mutable access to an occupied entry before any
/// potential inserts into the map.
///
/// # Examples
///
/// ```
/// #![feature(hash_raw_entry)]
/// use std::collections::HashMap;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
///
/// map.raw_entry_mut()
/// .from_key("poneyland")
/// .and_modify(|_k, v| { *v += 1 })
/// .or_insert("poneyland", 42);
/// assert_eq!(map["poneyland"], 42);
///
/// map.raw_entry_mut()
/// .from_key("poneyland")
/// .and_modify(|_k, v| { *v += 1 })
/// .or_insert("poneyland", 0);
/// assert_eq!(map["poneyland"], 43);
/// ```
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn and_modify<F>(self, f: F) -> Self
where
F: FnOnce(&mut K, &mut V),
{
match self {
RawEntryMut::Occupied(mut entry) => {
{
let (k, v) = entry.get_key_value_mut();
f(k, v);
}
RawEntryMut::Occupied(entry)
}
RawEntryMut::Vacant(entry) => RawEntryMut::Vacant(entry),
}
}
}
impl<'a, K, V> RawOccupiedEntryMut<'a, K, V> {
/// Gets a reference to the key in the entry.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn key(&self) -> &K {
self.base.key()
}
/// Gets a mutable reference to the key in the entry.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn key_mut(&mut self) -> &mut K {
self.base.key_mut()
}
/// Converts the entry into a mutable reference to the key in the entry
/// with a lifetime bound to the map itself.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn into_key(self) -> &'a mut K {
self.base.into_key()
}
/// Gets a reference to the value in the entry.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn get(&self) -> &V {
self.base.get()
}
/// Converts the OccupiedEntry into a mutable reference to the value in the entry
/// with a lifetime bound to the map itself.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn into_mut(self) -> &'a mut V {
self.base.into_mut()
}
/// Gets a mutable reference to the value in the entry.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn get_mut(&mut self) -> &mut V {
self.base.get_mut()
}
/// Gets a reference to the key and value in the entry.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn get_key_value(&mut self) -> (&K, &V) {
self.base.get_key_value()
}
/// Gets a mutable reference to the key and value in the entry.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn get_key_value_mut(&mut self) -> (&mut K, &mut V) {
self.base.get_key_value_mut()
}
/// Converts the OccupiedEntry into a mutable reference to the key and value in the entry
/// with a lifetime bound to the map itself.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn into_key_value(self) -> (&'a mut K, &'a mut V) {
self.base.into_key_value()
}
/// Sets the value of the entry, and returns the entry's old value.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn insert(&mut self, value: V) -> V {
self.base.insert(value)
}
/// Sets the value of the entry, and returns the entry's old value.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn insert_key(&mut self, key: K) -> K {
self.base.insert_key(key)
}
/// Takes the value out of the entry, and returns it.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn remove(self) -> V {
self.base.remove()
}
/// Take the ownership of the key and value from the map.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn remove_entry(self) -> (K, V) {
self.base.remove_entry()
}
}
impl<'a, K, V, S> RawVacantEntryMut<'a, K, V, S> {
/// Sets the value of the entry with the VacantEntry's key,
/// and returns a mutable reference to it.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn insert(self, key: K, value: V) -> (&'a mut K, &'a mut V)
where
K: Hash,
S: BuildHasher,
{
self.base.insert(key, value)
}
/// Sets the value of the entry with the VacantEntry's key,
/// and returns a mutable reference to it.
#[inline]
#[unstable(feature = "hash_raw_entry", issue = "56167")]
pub fn insert_hashed_nocheck(self, hash: u64, key: K, value: V) -> (&'a mut K, &'a mut V)
where
K: Hash,
S: BuildHasher,
{
self.base.insert_hashed_nocheck(hash, key, value)
}
}
#[unstable(feature = "hash_raw_entry", issue = "56167")]
impl<K, V, S> Debug for RawEntryBuilderMut<'_, K, V, S> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("RawEntryBuilder").finish()
}
}
#[unstable(feature = "hash_raw_entry", issue = "56167")]
impl<K: Debug, V: Debug, S> Debug for RawEntryMut<'_, K, V, S> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
RawEntryMut::Vacant(ref v) => f.debug_tuple("RawEntry").field(v).finish(),
RawEntryMut::Occupied(ref o) => f.debug_tuple("RawEntry").field(o).finish(),
}
}
}
#[unstable(feature = "hash_raw_entry", issue = "56167")]
impl<K: Debug, V: Debug> Debug for RawOccupiedEntryMut<'_, K, V> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("RawOccupiedEntryMut")
.field("key", self.key())
.field("value", self.get())
.finish()
}
}
#[unstable(feature = "hash_raw_entry", issue = "56167")]
impl<K, V, S> Debug for RawVacantEntryMut<'_, K, V, S> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("RawVacantEntryMut").finish()
}
}
#[unstable(feature = "hash_raw_entry", issue = "56167")]
impl<K, V, S> Debug for RawEntryBuilder<'_, K, V, S> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("RawEntryBuilder").finish()
}
}
/// A view into a single entry in a map, which may either be vacant or occupied.
///
/// This `enum` is constructed from the [`entry`] method on [`HashMap`].
///
/// [`HashMap`]: struct.HashMap.html
/// [`entry`]: struct.HashMap.html#method.entry
#[stable(feature = "rust1", since = "1.0.0")]
pub enum Entry<'a, K: 'a, V: 'a> {
/// An occupied entry.
#[stable(feature = "rust1", since = "1.0.0")]
Occupied(#[stable(feature = "rust1", since = "1.0.0")] OccupiedEntry<'a, K, V>),
/// A vacant entry.
#[stable(feature = "rust1", since = "1.0.0")]
Vacant(#[stable(feature = "rust1", since = "1.0.0")] VacantEntry<'a, K, V>),
}
#[stable(feature = "debug_hash_map", since = "1.12.0")]
impl<K: Debug, V: Debug> Debug for Entry<'_, K, V> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
Vacant(ref v) => f.debug_tuple("Entry").field(v).finish(),
Occupied(ref o) => f.debug_tuple("Entry").field(o).finish(),
}
}
}
/// A view into an occupied entry in a `HashMap`.
/// It is part of the [`Entry`] enum.
///
/// [`Entry`]: enum.Entry.html
#[stable(feature = "rust1", since = "1.0.0")]
pub struct OccupiedEntry<'a, K: 'a, V: 'a> {
base: base::RustcOccupiedEntry<'a, K, V>,
}
#[stable(feature = "debug_hash_map", since = "1.12.0")]
impl<K: Debug, V: Debug> Debug for OccupiedEntry<'_, K, V> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("OccupiedEntry").field("key", self.key()).field("value", self.get()).finish()
}
}
/// A view into a vacant entry in a `HashMap`.
/// It is part of the [`Entry`] enum.
///
/// [`Entry`]: enum.Entry.html
#[stable(feature = "rust1", since = "1.0.0")]
pub struct VacantEntry<'a, K: 'a, V: 'a> {
base: base::RustcVacantEntry<'a, K, V>,
}
#[stable(feature = "debug_hash_map", since = "1.12.0")]
impl<K: Debug, V> Debug for VacantEntry<'_, K, V> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_tuple("VacantEntry").field(self.key()).finish()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, K, V, S> IntoIterator for &'a HashMap<K, V, S> {
type Item = (&'a K, &'a V);
type IntoIter = Iter<'a, K, V>;
#[inline]
fn into_iter(self) -> Iter<'a, K, V> {
self.iter()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, K, V, S> IntoIterator for &'a mut HashMap<K, V, S> {
type Item = (&'a K, &'a mut V);
type IntoIter = IterMut<'a, K, V>;
#[inline]
fn into_iter(self) -> IterMut<'a, K, V> {
self.iter_mut()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V, S> IntoIterator for HashMap<K, V, S> {
type Item = (K, V);
type IntoIter = IntoIter<K, V>;
/// Creates a consuming iterator, that is, one that moves each key-value
/// pair out of the map in arbitrary order. The map cannot be used after
/// calling this.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map = HashMap::new();
/// map.insert("a", 1);
/// map.insert("b", 2);
/// map.insert("c", 3);
///
/// // Not possible with .iter()
/// let vec: Vec<(&str, i32)> = map.into_iter().collect();
/// ```
#[inline]
fn into_iter(self) -> IntoIter<K, V> {
IntoIter { base: self.base.into_iter() }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, K, V> Iterator for Iter<'a, K, V> {
type Item = (&'a K, &'a V);
#[inline]
fn next(&mut self) -> Option<(&'a K, &'a V)> {
self.base.next()
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.base.size_hint()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V> ExactSizeIterator for Iter<'_, K, V> {
#[inline]
fn len(&self) -> usize {
self.base.len()
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<K, V> FusedIterator for Iter<'_, K, V> {}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, K, V> Iterator for IterMut<'a, K, V> {
type Item = (&'a K, &'a mut V);
#[inline]
fn next(&mut self) -> Option<(&'a K, &'a mut V)> {
self.base.next()
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.base.size_hint()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V> ExactSizeIterator for IterMut<'_, K, V> {
#[inline]
fn len(&self) -> usize {
self.base.len()
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<K, V> FusedIterator for IterMut<'_, K, V> {}
#[stable(feature = "std_debug", since = "1.16.0")]
impl<K, V> fmt::Debug for IterMut<'_, K, V>
where
K: fmt::Debug,
V: fmt::Debug,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.iter()).finish()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V> Iterator for IntoIter<K, V> {
type Item = (K, V);
#[inline]
fn next(&mut self) -> Option<(K, V)> {
self.base.next()
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.base.size_hint()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V> ExactSizeIterator for IntoIter<K, V> {
#[inline]
fn len(&self) -> usize {
self.base.len()
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<K, V> FusedIterator for IntoIter<K, V> {}
#[stable(feature = "std_debug", since = "1.16.0")]
impl<K: Debug, V: Debug> fmt::Debug for IntoIter<K, V> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.iter()).finish()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, K, V> Iterator for Keys<'a, K, V> {
type Item = &'a K;
#[inline]
fn next(&mut self) -> Option<&'a K> {
self.inner.next().map(|(k, _)| k)
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V> ExactSizeIterator for Keys<'_, K, V> {
#[inline]
fn len(&self) -> usize {
self.inner.len()
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<K, V> FusedIterator for Keys<'_, K, V> {}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, K, V> Iterator for Values<'a, K, V> {
type Item = &'a V;
#[inline]
fn next(&mut self) -> Option<&'a V> {
self.inner.next().map(|(_, v)| v)
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V> ExactSizeIterator for Values<'_, K, V> {
#[inline]
fn len(&self) -> usize {
self.inner.len()
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<K, V> FusedIterator for Values<'_, K, V> {}
#[stable(feature = "map_values_mut", since = "1.10.0")]
impl<'a, K, V> Iterator for ValuesMut<'a, K, V> {
type Item = &'a mut V;
#[inline]
fn next(&mut self) -> Option<&'a mut V> {
self.inner.next().map(|(_, v)| v)
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
}
#[stable(feature = "map_values_mut", since = "1.10.0")]
impl<K, V> ExactSizeIterator for ValuesMut<'_, K, V> {
#[inline]
fn len(&self) -> usize {
self.inner.len()
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<K, V> FusedIterator for ValuesMut<'_, K, V> {}
#[stable(feature = "std_debug", since = "1.16.0")]
impl<K, V> fmt::Debug for ValuesMut<'_, K, V>
where
K: fmt::Debug,
V: fmt::Debug,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.inner.iter()).finish()
}
}
#[stable(feature = "drain", since = "1.6.0")]
impl<'a, K, V> Iterator for Drain<'a, K, V> {
type Item = (K, V);
#[inline]
fn next(&mut self) -> Option<(K, V)> {
self.base.next()
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.base.size_hint()
}
}
#[stable(feature = "drain", since = "1.6.0")]
impl<K, V> ExactSizeIterator for Drain<'_, K, V> {
#[inline]
fn len(&self) -> usize {
self.base.len()
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<K, V> FusedIterator for Drain<'_, K, V> {}
#[stable(feature = "std_debug", since = "1.16.0")]
impl<K, V> fmt::Debug for Drain<'_, K, V>
where
K: fmt::Debug,
V: fmt::Debug,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.iter()).finish()
}
}
impl<'a, K, V> Entry<'a, K, V> {
#[stable(feature = "rust1", since = "1.0.0")]
/// Ensures a value is in the entry by inserting the default if empty, and returns
/// a mutable reference to the value in the entry.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
///
/// map.entry("poneyland").or_insert(3);
/// assert_eq!(map["poneyland"], 3);
///
/// *map.entry("poneyland").or_insert(10) *= 2;
/// assert_eq!(map["poneyland"], 6);
/// ```
#[inline]
pub fn or_insert(self, default: V) -> &'a mut V {
match self {
Occupied(entry) => entry.into_mut(),
Vacant(entry) => entry.insert(default),
}
}
#[stable(feature = "rust1", since = "1.0.0")]
/// Ensures a value is in the entry by inserting the result of the default function if empty,
/// and returns a mutable reference to the value in the entry.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map: HashMap<&str, String> = HashMap::new();
/// let s = "hoho".to_string();
///
/// map.entry("poneyland").or_insert_with(|| s);
///
/// assert_eq!(map["poneyland"], "hoho".to_string());
/// ```
#[inline]
pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut V {
match self {
Occupied(entry) => entry.into_mut(),
Vacant(entry) => entry.insert(default()),
}
}
/// Returns a reference to this entry's key.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// assert_eq!(map.entry("poneyland").key(), &"poneyland");
/// ```
#[inline]
#[stable(feature = "map_entry_keys", since = "1.10.0")]
pub fn key(&self) -> &K {
match *self {
Occupied(ref entry) => entry.key(),
Vacant(ref entry) => entry.key(),
}
}
/// Provides in-place mutable access to an occupied entry before any
/// potential inserts into the map.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
///
/// map.entry("poneyland")
/// .and_modify(|e| { *e += 1 })
/// .or_insert(42);
/// assert_eq!(map["poneyland"], 42);
///
/// map.entry("poneyland")
/// .and_modify(|e| { *e += 1 })
/// .or_insert(42);
/// assert_eq!(map["poneyland"], 43);
/// ```
#[inline]
#[stable(feature = "entry_and_modify", since = "1.26.0")]
pub fn and_modify<F>(self, f: F) -> Self
where
F: FnOnce(&mut V),
{
match self {
Occupied(mut entry) => {
f(entry.get_mut());
Occupied(entry)
}
Vacant(entry) => Vacant(entry),
}
}
/// Sets the value of the entry, and returns an OccupiedEntry.
///
/// # Examples
///
/// ```
/// #![feature(entry_insert)]
/// use std::collections::HashMap;
///
/// let mut map: HashMap<&str, String> = HashMap::new();
/// let entry = map.entry("poneyland").insert("hoho".to_string());
///
/// assert_eq!(entry.key(), &"poneyland");
/// ```
#[inline]
#[unstable(feature = "entry_insert", issue = "65225")]
pub fn insert(self, value: V) -> OccupiedEntry<'a, K, V> {
match self {
Occupied(mut entry) => {
entry.insert(value);
entry
}
Vacant(entry) => entry.insert_entry(value),
}
}
}
impl<'a, K, V: Default> Entry<'a, K, V> {
#[stable(feature = "entry_or_default", since = "1.28.0")]
/// Ensures a value is in the entry by inserting the default value if empty,
/// and returns a mutable reference to the value in the entry.
///
/// # Examples
///
/// ```
/// # fn main() {
/// use std::collections::HashMap;
///
/// let mut map: HashMap<&str, Option<u32>> = HashMap::new();
/// map.entry("poneyland").or_default();
///
/// assert_eq!(map["poneyland"], None);
/// # }
/// ```
#[inline]
pub fn or_default(self) -> &'a mut V {
match self {
Occupied(entry) => entry.into_mut(),
Vacant(entry) => entry.insert(Default::default()),
}
}
}
impl<'a, K, V> OccupiedEntry<'a, K, V> {
/// Gets a reference to the key in the entry.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// map.entry("poneyland").or_insert(12);
/// assert_eq!(map.entry("poneyland").key(), &"poneyland");
/// ```
#[inline]
#[stable(feature = "map_entry_keys", since = "1.10.0")]
pub fn key(&self) -> &K {
self.base.key()
}
/// Take the ownership of the key and value from the map.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// use std::collections::hash_map::Entry;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// map.entry("poneyland").or_insert(12);
///
/// if let Entry::Occupied(o) = map.entry("poneyland") {
/// // We delete the entry from the map.
/// o.remove_entry();
/// }
///
/// assert_eq!(map.contains_key("poneyland"), false);
/// ```
#[inline]
#[stable(feature = "map_entry_recover_keys2", since = "1.12.0")]
pub fn remove_entry(self) -> (K, V) {
self.base.remove_entry()
}
/// Gets a reference to the value in the entry.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// use std::collections::hash_map::Entry;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// map.entry("poneyland").or_insert(12);
///
/// if let Entry::Occupied(o) = map.entry("poneyland") {
/// assert_eq!(o.get(), &12);
/// }
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn get(&self) -> &V {
self.base.get()
}
/// Gets a mutable reference to the value in the entry.
///
/// If you need a reference to the `OccupiedEntry` which may outlive the
/// destruction of the `Entry` value, see [`into_mut`].
///
/// [`into_mut`]: #method.into_mut
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// use std::collections::hash_map::Entry;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// map.entry("poneyland").or_insert(12);
///
/// assert_eq!(map["poneyland"], 12);
/// if let Entry::Occupied(mut o) = map.entry("poneyland") {
/// *o.get_mut() += 10;
/// assert_eq!(*o.get(), 22);
///
/// // We can use the same Entry multiple times.
/// *o.get_mut() += 2;
/// }
///
/// assert_eq!(map["poneyland"], 24);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn get_mut(&mut self) -> &mut V {
self.base.get_mut()
}
/// Converts the OccupiedEntry into a mutable reference to the value in the entry
/// with a lifetime bound to the map itself.
///
/// If you need multiple references to the `OccupiedEntry`, see [`get_mut`].
///
/// [`get_mut`]: #method.get_mut
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// use std::collections::hash_map::Entry;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// map.entry("poneyland").or_insert(12);
///
/// assert_eq!(map["poneyland"], 12);
/// if let Entry::Occupied(o) = map.entry("poneyland") {
/// *o.into_mut() += 10;
/// }
///
/// assert_eq!(map["poneyland"], 22);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn into_mut(self) -> &'a mut V {
self.base.into_mut()
}
/// Sets the value of the entry, and returns the entry's old value.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// use std::collections::hash_map::Entry;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// map.entry("poneyland").or_insert(12);
///
/// if let Entry::Occupied(mut o) = map.entry("poneyland") {
/// assert_eq!(o.insert(15), 12);
/// }
///
/// assert_eq!(map["poneyland"], 15);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn insert(&mut self, value: V) -> V {
self.base.insert(value)
}
/// Takes the value out of the entry, and returns it.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// use std::collections::hash_map::Entry;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// map.entry("poneyland").or_insert(12);
///
/// if let Entry::Occupied(o) = map.entry("poneyland") {
/// assert_eq!(o.remove(), 12);
/// }
///
/// assert_eq!(map.contains_key("poneyland"), false);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn remove(self) -> V {
self.base.remove()
}
/// Replaces the entry, returning the old key and value. The new key in the hash map will be
/// the key used to create this entry.
///
/// # Examples
///
/// ```
/// #![feature(map_entry_replace)]
/// use std::collections::hash_map::{Entry, HashMap};
/// use std::rc::Rc;
///
/// let mut map: HashMap<Rc<String>, u32> = HashMap::new();
/// map.insert(Rc::new("Stringthing".to_string()), 15);
///
/// let my_key = Rc::new("Stringthing".to_string());
///
/// if let Entry::Occupied(entry) = map.entry(my_key) {
/// // Also replace the key with a handle to our other key.
/// let (old_key, old_value): (Rc<String>, u32) = entry.replace_entry(16);
/// }
///
/// ```
#[inline]
#[unstable(feature = "map_entry_replace", issue = "44286")]
pub fn replace_entry(self, value: V) -> (K, V) {
self.base.replace_entry(value)
}
/// Replaces the key in the hash map with the key used to create this entry.
///
/// # Examples
///
/// ```
/// #![feature(map_entry_replace)]
/// use std::collections::hash_map::{Entry, HashMap};
/// use std::rc::Rc;
///
/// let mut map: HashMap<Rc<String>, u32> = HashMap::new();
/// let mut known_strings: Vec<Rc<String>> = Vec::new();
///
/// // Initialise known strings, run program, etc.
///
/// reclaim_memory(&mut map, &known_strings);
///
/// fn reclaim_memory(map: &mut HashMap<Rc<String>, u32>, known_strings: &[Rc<String>] ) {
/// for s in known_strings {
/// if let Entry::Occupied(entry) = map.entry(s.clone()) {
/// // Replaces the entry's key with our version of it in `known_strings`.
/// entry.replace_key();
/// }
/// }
/// }
/// ```
#[inline]
#[unstable(feature = "map_entry_replace", issue = "44286")]
pub fn replace_key(self) -> K {
self.base.replace_key()
}
}
impl<'a, K: 'a, V: 'a> VacantEntry<'a, K, V> {
/// Gets a reference to the key that would be used when inserting a value
/// through the `VacantEntry`.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
/// assert_eq!(map.entry("poneyland").key(), &"poneyland");
/// ```
#[inline]
#[stable(feature = "map_entry_keys", since = "1.10.0")]
pub fn key(&self) -> &K {
self.base.key()
}
/// Take ownership of the key.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// use std::collections::hash_map::Entry;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
///
/// if let Entry::Vacant(v) = map.entry("poneyland") {
/// v.into_key();
/// }
/// ```
#[inline]
#[stable(feature = "map_entry_recover_keys2", since = "1.12.0")]
pub fn into_key(self) -> K {
self.base.into_key()
}
/// Sets the value of the entry with the VacantEntry's key,
/// and returns a mutable reference to it.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// use std::collections::hash_map::Entry;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
///
/// if let Entry::Vacant(o) = map.entry("poneyland") {
/// o.insert(37);
/// }
/// assert_eq!(map["poneyland"], 37);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub fn insert(self, value: V) -> &'a mut V {
self.base.insert(value)
}
/// Sets the value of the entry with the VacantEntry's key,
/// and returns an OccupiedEntry.
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// use std::collections::hash_map::Entry;
///
/// let mut map: HashMap<&str, u32> = HashMap::new();
///
/// if let Entry::Vacant(o) = map.entry("poneyland") {
/// o.insert(37);
/// }
/// assert_eq!(map["poneyland"], 37);
/// ```
#[inline]
fn insert_entry(self, value: V) -> OccupiedEntry<'a, K, V> {
let base = self.base.insert_entry(value);
OccupiedEntry { base }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V, S> FromIterator<(K, V)> for HashMap<K, V, S>
where
K: Eq + Hash,
S: BuildHasher + Default,
{
fn from_iter<T: IntoIterator<Item = (K, V)>>(iter: T) -> HashMap<K, V, S> {
let mut map = HashMap::with_hasher(Default::default());
map.extend(iter);
map
}
}
/// Inserts all new key-values from the iterator and replaces values with existing
/// keys with new values returned from the iterator.
#[stable(feature = "rust1", since = "1.0.0")]
impl<K, V, S> Extend<(K, V)> for HashMap<K, V, S>
where
K: Eq + Hash,
S: BuildHasher,
{
#[inline]
fn extend<T: IntoIterator<Item = (K, V)>>(&mut self, iter: T) {
self.base.extend(iter)
}
}
#[stable(feature = "hash_extend_copy", since = "1.4.0")]
impl<'a, K, V, S> Extend<(&'a K, &'a V)> for HashMap<K, V, S>
where
K: Eq + Hash + Copy,
V: Copy,
S: BuildHasher,
{
#[inline]
fn extend<T: IntoIterator<Item = (&'a K, &'a V)>>(&mut self, iter: T) {
self.base.extend(iter)
}
}
/// `RandomState` is the default state for [`HashMap`] types.
///
/// A particular instance `RandomState` will create the same instances of
/// [`Hasher`], but the hashers created by two different `RandomState`
/// instances are unlikely to produce the same result for the same values.
///
/// [`HashMap`]: struct.HashMap.html
/// [`Hasher`]: ../../hash/trait.Hasher.html
///
/// # Examples
///
/// ```
/// use std::collections::HashMap;
/// use std::collections::hash_map::RandomState;
///
/// let s = RandomState::new();
/// let mut map = HashMap::with_hasher(s);
/// map.insert(1, 2);
/// ```
#[derive(Clone)]
#[stable(feature = "hashmap_build_hasher", since = "1.7.0")]
pub struct RandomState {
k0: u64,
k1: u64,
}
impl RandomState {
/// Constructs a new `RandomState` that is initialized with random keys.
///
/// # Examples
///
/// ```
/// use std::collections::hash_map::RandomState;
///
/// let s = RandomState::new();
/// ```
#[inline]
#[allow(deprecated)]
// rand
#[stable(feature = "hashmap_build_hasher", since = "1.7.0")]
pub fn new() -> RandomState {
// Historically this function did not cache keys from the OS and instead
// simply always called `rand::thread_rng().gen()` twice. In #31356 it
// was discovered, however, that because we re-seed the thread-local RNG
// from the OS periodically that this can cause excessive slowdown when
// many hash maps are created on a thread. To solve this performance
// trap we cache the first set of randomly generated keys per-thread.
//
// Later in #36481 it was discovered that exposing a deterministic
// iteration order allows a form of DOS attack. To counter that we
// increment one of the seeds on every RandomState creation, giving
// every corresponding HashMap a different iteration order.
thread_local!(static KEYS: Cell<(u64, u64)> = {
Cell::new(sys::hashmap_random_keys())
});
KEYS.with(|keys| {
let (k0, k1) = keys.get();
keys.set((k0.wrapping_add(1), k1));
RandomState { k0, k1 }
})
}
}
#[stable(feature = "hashmap_build_hasher", since = "1.7.0")]
impl BuildHasher for RandomState {
type Hasher = DefaultHasher;
#[inline]
#[allow(deprecated)]
fn build_hasher(&self) -> DefaultHasher {
DefaultHasher(SipHasher13::new_with_keys(self.k0, self.k1))
}
}
/// The default [`Hasher`] used by [`RandomState`].
///
/// The internal algorithm is not specified, and so it and its hashes should
/// not be relied upon over releases.
///
/// [`RandomState`]: struct.RandomState.html
/// [`Hasher`]: ../../hash/trait.Hasher.html
#[stable(feature = "hashmap_default_hasher", since = "1.13.0")]
#[allow(deprecated)]
#[derive(Clone, Debug)]
pub struct DefaultHasher(SipHasher13);
impl DefaultHasher {
/// Creates a new `DefaultHasher`.
///
/// This hasher is not guaranteed to be the same as all other
/// `DefaultHasher` instances, but is the same as all other `DefaultHasher`
/// instances created through `new` or `default`.
#[stable(feature = "hashmap_default_hasher", since = "1.13.0")]
#[allow(deprecated)]
pub fn new() -> DefaultHasher {
DefaultHasher(SipHasher13::new_with_keys(0, 0))
}
}
#[stable(feature = "hashmap_default_hasher", since = "1.13.0")]
impl Default for DefaultHasher {
// FIXME: here should link `new` to [DefaultHasher::new], but it occurs intra-doc link
// resolution failure when re-exporting libstd items. When #56922 fixed,
// link `new` to [DefaultHasher::new] again.
/// Creates a new `DefaultHasher` using `new`.
/// See its documentation for more.
fn default() -> DefaultHasher {
DefaultHasher::new()
}
}
#[stable(feature = "hashmap_default_hasher", since = "1.13.0")]
impl Hasher for DefaultHasher {
#[inline]
fn write(&mut self, msg: &[u8]) {
self.0.write(msg)
}
#[inline]
fn finish(&self) -> u64 {
self.0.finish()
}
}
#[stable(feature = "hashmap_build_hasher", since = "1.7.0")]
impl Default for RandomState {
/// Constructs a new `RandomState`.
#[inline]
fn default() -> RandomState {
RandomState::new()
}
}
#[stable(feature = "std_debug", since = "1.16.0")]
impl fmt::Debug for RandomState {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.pad("RandomState { .. }")
}
}
#[inline]
fn map_entry<'a, K: 'a, V: 'a>(raw: base::RustcEntry<'a, K, V>) -> Entry<'a, K, V> {
match raw {
base::RustcEntry::Occupied(base) => Entry::Occupied(OccupiedEntry { base }),
base::RustcEntry::Vacant(base) => Entry::Vacant(VacantEntry { base }),
}
}
#[inline]
fn map_collection_alloc_err(err: hashbrown::CollectionAllocErr) -> TryReserveError {
match err {
hashbrown::CollectionAllocErr::CapacityOverflow => TryReserveError::CapacityOverflow,
hashbrown::CollectionAllocErr::AllocErr { layout } => {
TryReserveError::AllocError { layout, non_exhaustive: () }
}
}
}
#[inline]
fn map_raw_entry<'a, K: 'a, V: 'a, S: 'a>(
raw: base::RawEntryMut<'a, K, V, S>,
) -> RawEntryMut<'a, K, V, S> {
match raw {
base::RawEntryMut::Occupied(base) => RawEntryMut::Occupied(RawOccupiedEntryMut { base }),
base::RawEntryMut::Vacant(base) => RawEntryMut::Vacant(RawVacantEntryMut { base }),
}
}
#[allow(dead_code)]
fn assert_covariance() {
fn map_key<'new>(v: HashMap<&'static str, u8>) -> HashMap<&'new str, u8> {
v
}
fn map_val<'new>(v: HashMap<u8, &'static str>) -> HashMap<u8, &'new str> {
v
}
fn iter_key<'a, 'new>(v: Iter<'a, &'static str, u8>) -> Iter<'a, &'new str, u8> {
v
}
fn iter_val<'a, 'new>(v: Iter<'a, u8, &'static str>) -> Iter<'a, u8, &'new str> {
v
}
fn into_iter_key<'new>(v: IntoIter<&'static str, u8>) -> IntoIter<&'new str, u8> {
v
}
fn into_iter_val<'new>(v: IntoIter<u8, &'static str>) -> IntoIter<u8, &'new str> {
v
}
fn keys_key<'a, 'new>(v: Keys<'a, &'static str, u8>) -> Keys<'a, &'new str, u8> {
v
}
fn keys_val<'a, 'new>(v: Keys<'a, u8, &'static str>) -> Keys<'a, u8, &'new str> {
v
}
fn values_key<'a, 'new>(v: Values<'a, &'static str, u8>) -> Values<'a, &'new str, u8> {
v
}
fn values_val<'a, 'new>(v: Values<'a, u8, &'static str>) -> Values<'a, u8, &'new str> {
v
}
fn drain<'new>(
d: Drain<'static, &'static str, &'static str>,
) -> Drain<'new, &'new str, &'new str> {
d
}
}
#[cfg(test)]
mod test_map {
use super::Entry::{Occupied, Vacant};
use super::HashMap;
use super::RandomState;
use crate::cell::RefCell;
use rand::{thread_rng, Rng};
use realstd::collections::TryReserveError::*;
use realstd::usize;
// https://github.com/rust-lang/rust/issues/62301
fn _assert_hashmap_is_unwind_safe() {
fn assert_unwind_safe<T: crate::panic::UnwindSafe>() {}
assert_unwind_safe::<HashMap<(), crate::cell::UnsafeCell<()>>>();
}
#[test]
fn test_zero_capacities() {
type HM = HashMap<i32, i32>;
let m = HM::new();
assert_eq!(m.capacity(), 0);
let m = HM::default();
assert_eq!(m.capacity(), 0);
let m = HM::with_hasher(RandomState::new());
assert_eq!(m.capacity(), 0);
let m = HM::with_capacity(0);
assert_eq!(m.capacity(), 0);
let m = HM::with_capacity_and_hasher(0, RandomState::new());
assert_eq!(m.capacity(), 0);
let mut m = HM::new();
m.insert(1, 1);
m.insert(2, 2);
m.remove(&1);
m.remove(&2);
m.shrink_to_fit();
assert_eq!(m.capacity(), 0);
let mut m = HM::new();
m.reserve(0);
assert_eq!(m.capacity(), 0);
}
#[test]
fn test_create_capacity_zero() {
let mut m = HashMap::with_capacity(0);
assert!(m.insert(1, 1).is_none());
assert!(m.contains_key(&1));
assert!(!m.contains_key(&0));
}
#[test]
fn test_insert() {
let mut m = HashMap::new();
assert_eq!(m.len(), 0);
assert!(m.insert(1, 2).is_none());
assert_eq!(m.len(), 1);
assert!(m.insert(2, 4).is_none());
assert_eq!(m.len(), 2);
assert_eq!(*m.get(&1).unwrap(), 2);
assert_eq!(*m.get(&2).unwrap(), 4);
}
#[test]
fn test_clone() {
let mut m = HashMap::new();
assert_eq!(m.len(), 0);
assert!(m.insert(1, 2).is_none());
assert_eq!(m.len(), 1);
assert!(m.insert(2, 4).is_none());
assert_eq!(m.len(), 2);
let m2 = m.clone();
assert_eq!(*m2.get(&1).unwrap(), 2);
assert_eq!(*m2.get(&2).unwrap(), 4);
assert_eq!(m2.len(), 2);
}
thread_local! { static DROP_VECTOR: RefCell<Vec<i32>> = RefCell::new(Vec::new()) }
#[derive(Hash, PartialEq, Eq)]
struct Droppable {
k: usize,
}
impl Droppable {
fn new(k: usize) -> Droppable {
DROP_VECTOR.with(|slot| {
slot.borrow_mut()[k] += 1;
});
Droppable { k }
}
}
impl Drop for Droppable {
fn drop(&mut self) {
DROP_VECTOR.with(|slot| {
slot.borrow_mut()[self.k] -= 1;
});
}
}
impl Clone for Droppable {
fn clone(&self) -> Droppable {
Droppable::new(self.k)
}
}
#[test]
fn test_drops() {
DROP_VECTOR.with(|slot| {
*slot.borrow_mut() = vec![0; 200];
});
{
let mut m = HashMap::new();
DROP_VECTOR.with(|v| {
for i in 0..200 {
assert_eq!(v.borrow()[i], 0);
}
});
for i in 0..100 {
let d1 = Droppable::new(i);
let d2 = Droppable::new(i + 100);
m.insert(d1, d2);
}
DROP_VECTOR.with(|v| {
for i in 0..200 {
assert_eq!(v.borrow()[i], 1);
}
});
for i in 0..50 {
let k = Droppable::new(i);
let v = m.remove(&k);
assert!(v.is_some());
DROP_VECTOR.with(|v| {
assert_eq!(v.borrow()[i], 1);
assert_eq!(v.borrow()[i + 100], 1);
});
}
DROP_VECTOR.with(|v| {
for i in 0..50 {
assert_eq!(v.borrow()[i], 0);
assert_eq!(v.borrow()[i + 100], 0);
}
for i in 50..100 {
assert_eq!(v.borrow()[i], 1);
assert_eq!(v.borrow()[i + 100], 1);
}
});
}
DROP_VECTOR.with(|v| {
for i in 0..200 {
assert_eq!(v.borrow()[i], 0);
}
});
}
#[test]
fn test_into_iter_drops() {
DROP_VECTOR.with(|v| {
*v.borrow_mut() = vec![0; 200];
});
let hm = {
let mut hm = HashMap::new();
DROP_VECTOR.with(|v| {
for i in 0..200 {
assert_eq!(v.borrow()[i], 0);
}
});
for i in 0..100 {
let d1 = Droppable::new(i);
let d2 = Droppable::new(i + 100);
hm.insert(d1, d2);
}
DROP_VECTOR.with(|v| {
for i in 0..200 {
assert_eq!(v.borrow()[i], 1);
}
});
hm
};
// By the way, ensure that cloning doesn't screw up the dropping.
drop(hm.clone());
{
let mut half = hm.into_iter().take(50);
DROP_VECTOR.with(|v| {
for i in 0..200 {
assert_eq!(v.borrow()[i], 1);
}
});
for _ in half.by_ref() {}
DROP_VECTOR.with(|v| {
let nk = (0..100).filter(|&i| v.borrow()[i] == 1).count();
let nv = (0..100).filter(|&i| v.borrow()[i + 100] == 1).count();
assert_eq!(nk, 50);
assert_eq!(nv, 50);
});
};
DROP_VECTOR.with(|v| {
for i in 0..200 {
assert_eq!(v.borrow()[i], 0);
}
});
}
#[test]
fn test_empty_remove() {
let mut m: HashMap<i32, bool> = HashMap::new();
assert_eq!(m.remove(&0), None);
}
#[test]
fn test_empty_entry() {
let mut m: HashMap<i32, bool> = HashMap::new();
match m.entry(0) {
Occupied(_) => panic!(),
Vacant(_) => {}
}
assert!(*m.entry(0).or_insert(true));
assert_eq!(m.len(), 1);
}
#[test]
fn test_empty_iter() {
let mut m: HashMap<i32, bool> = HashMap::new();
assert_eq!(m.drain().next(), None);
assert_eq!(m.keys().next(), None);
assert_eq!(m.values().next(), None);
assert_eq!(m.values_mut().next(), None);
assert_eq!(m.iter().next(), None);
assert_eq!(m.iter_mut().next(), None);
assert_eq!(m.len(), 0);
assert!(m.is_empty());
assert_eq!(m.into_iter().next(), None);
}
#[test]
fn test_lots_of_insertions() {
let mut m = HashMap::new();
// Try this a few times to make sure we never screw up the hashmap's
// internal state.
for _ in 0..10 {
assert!(m.is_empty());
for i in 1..1001 {
assert!(m.insert(i, i).is_none());
for j in 1..=i {
let r = m.get(&j);
assert_eq!(r, Some(&j));
}
for j in i + 1..1001 {
let r = m.get(&j);
assert_eq!(r, None);
}
}
for i in 1001..2001 {
assert!(!m.contains_key(&i));
}
// remove forwards
for i in 1..1001 {
assert!(m.remove(&i).is_some());
for j in 1..=i {
assert!(!m.contains_key(&j));
}
for j in i + 1..1001 {
assert!(m.contains_key(&j));
}
}
for i in 1..1001 {
assert!(!m.contains_key(&i));
}
for i in 1..1001 {
assert!(m.insert(i, i).is_none());
}
// remove backwards
for i in (1..1001).rev() {
assert!(m.remove(&i).is_some());
for j in i..1001 {
assert!(!m.contains_key(&j));
}
for j in 1..i {
assert!(m.contains_key(&j));
}
}
}
}
#[test]
fn test_find_mut() {
let mut m = HashMap::new();
assert!(m.insert(1, 12).is_none());
assert!(m.insert(2, 8).is_none());
assert!(m.insert(5, 14).is_none());
let new = 100;
match m.get_mut(&5) {
None => panic!(),
Some(x) => *x = new,
}
assert_eq!(m.get(&5), Some(&new));
}
#[test]
fn test_insert_overwrite() {
let mut m = HashMap::new();
assert!(m.insert(1, 2).is_none());
assert_eq!(*m.get(&1).unwrap(), 2);
assert!(!m.insert(1, 3).is_none());
assert_eq!(*m.get(&1).unwrap(), 3);
}
#[test]
fn test_insert_conflicts() {
let mut m = HashMap::with_capacity(4);
assert!(m.insert(1, 2).is_none());
assert!(m.insert(5, 3).is_none());
assert!(m.insert(9, 4).is_none());
assert_eq!(*m.get(&9).unwrap(), 4);
assert_eq!(*m.get(&5).unwrap(), 3);
assert_eq!(*m.get(&1).unwrap(), 2);
}
#[test]
fn test_conflict_remove() {
let mut m = HashMap::with_capacity(4);
assert!(m.insert(1, 2).is_none());
assert_eq!(*m.get(&1).unwrap(), 2);
assert!(m.insert(5, 3).is_none());
assert_eq!(*m.get(&1).unwrap(), 2);
assert_eq!(*m.get(&5).unwrap(), 3);
assert!(m.insert(9, 4).is_none());
assert_eq!(*m.get(&1).unwrap(), 2);
assert_eq!(*m.get(&5).unwrap(), 3);
assert_eq!(*m.get(&9).unwrap(), 4);
assert!(m.remove(&1).is_some());
assert_eq!(*m.get(&9).unwrap(), 4);
assert_eq!(*m.get(&5).unwrap(), 3);
}
#[test]
fn test_is_empty() {
let mut m = HashMap::with_capacity(4);
assert!(m.insert(1, 2).is_none());
assert!(!m.is_empty());
assert!(m.remove(&1).is_some());
assert!(m.is_empty());
}
#[test]
fn test_remove() {
let mut m = HashMap::new();
m.insert(1, 2);
assert_eq!(m.remove(&1), Some(2));
assert_eq!(m.remove(&1), None);
}
#[test]
fn test_remove_entry() {
let mut m = HashMap::new();
m.insert(1, 2);
assert_eq!(m.remove_entry(&1), Some((1, 2)));
assert_eq!(m.remove(&1), None);
}
#[test]
fn test_iterate() {
let mut m = HashMap::with_capacity(4);
for i in 0..32 {
assert!(m.insert(i, i * 2).is_none());
}
assert_eq!(m.len(), 32);
let mut observed: u32 = 0;
for (k, v) in &m {
assert_eq!(*v, *k * 2);
observed |= 1 << *k;
}
assert_eq!(observed, 0xFFFF_FFFF);
}
#[test]
fn test_keys() {
let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')];
let map: HashMap<_, _> = vec.into_iter().collect();
let keys: Vec<_> = map.keys().cloned().collect();
assert_eq!(keys.len(), 3);
assert!(keys.contains(&1));
assert!(keys.contains(&2));
assert!(keys.contains(&3));
}
#[test]
fn test_values() {
let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')];
let map: HashMap<_, _> = vec.into_iter().collect();
let values: Vec<_> = map.values().cloned().collect();
assert_eq!(values.len(), 3);
assert!(values.contains(&'a'));
assert!(values.contains(&'b'));
assert!(values.contains(&'c'));
}
#[test]
fn test_values_mut() {
let vec = vec![(1, 1), (2, 2), (3, 3)];
let mut map: HashMap<_, _> = vec.into_iter().collect();
for value in map.values_mut() {
*value = (*value) * 2
}
let values: Vec<_> = map.values().cloned().collect();
assert_eq!(values.len(), 3);
assert!(values.contains(&2));
assert!(values.contains(&4));
assert!(values.contains(&6));
}
#[test]
fn test_find() {
let mut m = HashMap::new();
assert!(m.get(&1).is_none());
m.insert(1, 2);
match m.get(&1) {
None => panic!(),
Some(v) => assert_eq!(*v, 2),
}
}
#[test]
fn test_eq() {
let mut m1 = HashMap::new();
m1.insert(1, 2);
m1.insert(2, 3);
m1.insert(3, 4);
let mut m2 = HashMap::new();
m2.insert(1, 2);
m2.insert(2, 3);
assert!(m1 != m2);
m2.insert(3, 4);
assert_eq!(m1, m2);
}
#[test]
fn test_show() {
let mut map = HashMap::new();
let empty: HashMap<i32, i32> = HashMap::new();
map.insert(1, 2);
map.insert(3, 4);
let map_str = format!("{:?}", map);
assert!(map_str == "{1: 2, 3: 4}" || map_str == "{3: 4, 1: 2}");
assert_eq!(format!("{:?}", empty), "{}");
}
#[test]
fn test_reserve_shrink_to_fit() {
let mut m = HashMap::new();
m.insert(0, 0);
m.remove(&0);
assert!(m.capacity() >= m.len());
for i in 0..128 {
m.insert(i, i);
}
m.reserve(256);
let usable_cap = m.capacity();
for i in 128..(128 + 256) {
m.insert(i, i);
assert_eq!(m.capacity(), usable_cap);
}
for i in 100..(128 + 256) {
assert_eq!(m.remove(&i), Some(i));
}
m.shrink_to_fit();
assert_eq!(m.len(), 100);
assert!(!m.is_empty());
assert!(m.capacity() >= m.len());
for i in 0..100 {
assert_eq!(m.remove(&i), Some(i));
}
m.shrink_to_fit();
m.insert(0, 0);
assert_eq!(m.len(), 1);
assert!(m.capacity() >= m.len());
assert_eq!(m.remove(&0), Some(0));
}
#[test]
fn test_from_iter() {
let xs = [(1, 1), (2, 2), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
let map: HashMap<_, _> = xs.iter().cloned().collect();
for &(k, v) in &xs {
assert_eq!(map.get(&k), Some(&v));
}
assert_eq!(map.iter().len(), xs.len() - 1);
}
#[test]
fn test_size_hint() {
let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
let map: HashMap<_, _> = xs.iter().cloned().collect();
let mut iter = map.iter();
for _ in iter.by_ref().take(3) {}
assert_eq!(iter.size_hint(), (3, Some(3)));
}
#[test]
fn test_iter_len() {
let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
let map: HashMap<_, _> = xs.iter().cloned().collect();
let mut iter = map.iter();
for _ in iter.by_ref().take(3) {}
assert_eq!(iter.len(), 3);
}
#[test]
fn test_mut_size_hint() {
let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
let mut map: HashMap<_, _> = xs.iter().cloned().collect();
let mut iter = map.iter_mut();
for _ in iter.by_ref().take(3) {}
assert_eq!(iter.size_hint(), (3, Some(3)));
}
#[test]
fn test_iter_mut_len() {
let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
let mut map: HashMap<_, _> = xs.iter().cloned().collect();
let mut iter = map.iter_mut();
for _ in iter.by_ref().take(3) {}
assert_eq!(iter.len(), 3);
}
#[test]
fn test_index() {
let mut map = HashMap::new();
map.insert(1, 2);
map.insert(2, 1);
map.insert(3, 4);
assert_eq!(map[&2], 1);
}
#[test]
#[should_panic]
fn test_index_nonexistent() {
let mut map = HashMap::new();
map.insert(1, 2);
map.insert(2, 1);
map.insert(3, 4);
map[&4];
}
#[test]
fn test_entry() {
let xs = [(1, 10), (2, 20), (3, 30), (4, 40), (5, 50), (6, 60)];
let mut map: HashMap<_, _> = xs.iter().cloned().collect();
// Existing key (insert)
match map.entry(1) {
Vacant(_) => unreachable!(),
Occupied(mut view) => {
assert_eq!(view.get(), &10);
assert_eq!(view.insert(100), 10);
}
}
assert_eq!(map.get(&1).unwrap(), &100);
assert_eq!(map.len(), 6);
// Existing key (update)
match map.entry(2) {
Vacant(_) => unreachable!(),
Occupied(mut view) => {
let v = view.get_mut();
let new_v = (*v) * 10;
*v = new_v;
}
}
assert_eq!(map.get(&2).unwrap(), &200);
assert_eq!(map.len(), 6);
// Existing key (take)
match map.entry(3) {
Vacant(_) => unreachable!(),
Occupied(view) => {
assert_eq!(view.remove(), 30);
}
}
assert_eq!(map.get(&3), None);
assert_eq!(map.len(), 5);
// Inexistent key (insert)
match map.entry(10) {
Occupied(_) => unreachable!(),
Vacant(view) => {
assert_eq!(*view.insert(1000), 1000);
}
}
assert_eq!(map.get(&10).unwrap(), &1000);
assert_eq!(map.len(), 6);
}
#[test]
fn test_entry_take_doesnt_corrupt() {
#![allow(deprecated)] //rand
// Test for #19292
fn check(m: &HashMap<i32, ()>) {
for k in m.keys() {
assert!(m.contains_key(k), "{} is in keys() but not in the map?", k);
}
}
let mut m = HashMap::new();
let mut rng = thread_rng();
// Populate the map with some items.
for _ in 0..50 {
let x = rng.gen_range(-10, 10);
m.insert(x, ());
}
for _ in 0..1000 {
let x = rng.gen_range(-10, 10);
match m.entry(x) {
Vacant(_) => {}
Occupied(e) => {
e.remove();
}
}
check(&m);
}
}
#[test]
fn test_extend_ref() {
let mut a = HashMap::new();
a.insert(1, "one");
let mut b = HashMap::new();
b.insert(2, "two");
b.insert(3, "three");
a.extend(&b);
assert_eq!(a.len(), 3);
assert_eq!(a[&1], "one");
assert_eq!(a[&2], "two");
assert_eq!(a[&3], "three");
}
#[test]
fn test_capacity_not_less_than_len() {
let mut a = HashMap::new();
let mut item = 0;
for _ in 0..116 {
a.insert(item, 0);
item += 1;
}
assert!(a.capacity() > a.len());
let free = a.capacity() - a.len();
for _ in 0..free {
a.insert(item, 0);
item += 1;
}
assert_eq!(a.len(), a.capacity());
// Insert at capacity should cause allocation.
a.insert(item, 0);
assert!(a.capacity() > a.len());
}
#[test]
fn test_occupied_entry_key() {
let mut a = HashMap::new();
let key = "hello there";
let value = "value goes here";
assert!(a.is_empty());
a.insert(key.clone(), value.clone());
assert_eq!(a.len(), 1);
assert_eq!(a[key], value);
match a.entry(key.clone()) {
Vacant(_) => panic!(),
Occupied(e) => assert_eq!(key, *e.key()),
}
assert_eq!(a.len(), 1);
assert_eq!(a[key], value);
}
#[test]
fn test_vacant_entry_key() {
let mut a = HashMap::new();
let key = "hello there";
let value = "value goes here";
assert!(a.is_empty());
match a.entry(key.clone()) {
Occupied(_) => panic!(),
Vacant(e) => {
assert_eq!(key, *e.key());
e.insert(value.clone());
}
}
assert_eq!(a.len(), 1);
assert_eq!(a[key], value);
}
#[test]
fn test_retain() {
let mut map: HashMap<i32, i32> = (0..100).map(|x| (x, x * 10)).collect();
map.retain(|&k, _| k % 2 == 0);
assert_eq!(map.len(), 50);
assert_eq!(map[&2], 20);
assert_eq!(map[&4], 40);
assert_eq!(map[&6], 60);
}
#[test]
fn test_try_reserve() {
let mut empty_bytes: HashMap<u8, u8> = HashMap::new();
const MAX_USIZE: usize = usize::MAX;
if let Err(CapacityOverflow) = empty_bytes.try_reserve(MAX_USIZE) {
} else {
panic!("usize::MAX should trigger an overflow!");
}
if let Err(AllocError { .. }) = empty_bytes.try_reserve(MAX_USIZE / 8) {
} else {
panic!("usize::MAX / 8 should trigger an OOM!")
}
}
#[test]
fn test_raw_entry() {
use super::RawEntryMut::{Occupied, Vacant};
let xs = [(1i32, 10i32), (2, 20), (3, 30), (4, 40), (5, 50), (6, 60)];
let mut map: HashMap<_, _> = xs.iter().cloned().collect();
let compute_hash = |map: &HashMap<i32, i32>, k: i32| -> u64 {
use core::hash::{BuildHasher, Hash, Hasher};
let mut hasher = map.hasher().build_hasher();
k.hash(&mut hasher);
hasher.finish()
};
// Existing key (insert)
match map.raw_entry_mut().from_key(&1) {
Vacant(_) => unreachable!(),
Occupied(mut view) => {
assert_eq!(view.get(), &10);
assert_eq!(view.insert(100), 10);
}
}
let hash1 = compute_hash(&map, 1);
assert_eq!(map.raw_entry().from_key(&1).unwrap(), (&1, &100));
assert_eq!(map.raw_entry().from_hash(hash1, |k| *k == 1).unwrap(), (&1, &100));
assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash1, &1).unwrap(), (&1, &100));
assert_eq!(map.len(), 6);
// Existing key (update)
match map.raw_entry_mut().from_key(&2) {
Vacant(_) => unreachable!(),
Occupied(mut view) => {
let v = view.get_mut();
let new_v = (*v) * 10;
*v = new_v;
}
}
let hash2 = compute_hash(&map, 2);
assert_eq!(map.raw_entry().from_key(&2).unwrap(), (&2, &200));
assert_eq!(map.raw_entry().from_hash(hash2, |k| *k == 2).unwrap(), (&2, &200));
assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash2, &2).unwrap(), (&2, &200));
assert_eq!(map.len(), 6);
// Existing key (take)
let hash3 = compute_hash(&map, 3);
match map.raw_entry_mut().from_key_hashed_nocheck(hash3, &3) {
Vacant(_) => unreachable!(),
Occupied(view) => {
assert_eq!(view.remove_entry(), (3, 30));
}
}
assert_eq!(map.raw_entry().from_key(&3), None);
assert_eq!(map.raw_entry().from_hash(hash3, |k| *k == 3), None);
assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash3, &3), None);
assert_eq!(map.len(), 5);
// Nonexistent key (insert)
match map.raw_entry_mut().from_key(&10) {
Occupied(_) => unreachable!(),
Vacant(view) => {
assert_eq!(view.insert(10, 1000), (&mut 10, &mut 1000));
}
}
assert_eq!(map.raw_entry().from_key(&10).unwrap(), (&10, &1000));
assert_eq!(map.len(), 6);
// Ensure all lookup methods produce equivalent results.
for k in 0..12 {
let hash = compute_hash(&map, k);
let v = map.get(&k).cloned();
let kv = v.as_ref().map(|v| (&k, v));
assert_eq!(map.raw_entry().from_key(&k), kv);
assert_eq!(map.raw_entry().from_hash(hash, |q| *q == k), kv);
assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash, &k), kv);
match map.raw_entry_mut().from_key(&k) {
Occupied(mut o) => assert_eq!(Some(o.get_key_value()), kv),
Vacant(_) => assert_eq!(v, None),
}
match map.raw_entry_mut().from_key_hashed_nocheck(hash, &k) {
Occupied(mut o) => assert_eq!(Some(o.get_key_value()), kv),
Vacant(_) => assert_eq!(v, None),
}
match map.raw_entry_mut().from_hash(hash, |q| *q == k) {
Occupied(mut o) => assert_eq!(Some(o.get_key_value()), kv),
Vacant(_) => assert_eq!(v, None),
}
}
}
}Alors la programmation fonctionnelle "pure" que c'est super maintenable... lol ou pas lol selon vous ? Je le redis mais pour moi, c'est un cancer.
Je me souviens que je disais en 2010 à @Roger quelque chose du type :
La programmation fonctionnelle est un cancer.
Heureusement, dix ans plus tard j'ai quand même un peu changé d'avis sur la question, je dirais aujourd'hui :
La programmation fonctionnelle "pure" est un cancer.
La différence étant que je suis en mesure d'argumenter le ressenti inconscient que j'avais à l'époque. Depuis le bouquin sur les design-patterns du Gang of Four, nous avons eu une pléthore d'autres auteurs qui nous ont expliqué pourquoi il faut toujours dépendre des interfaces et jamais des implémentations. Le problème avec ça, c'est qu'une grande partie des développeurs ne comprennent pas bien ce que sont les implémentations et surtout pourquoi il ne faut pas dépendre d'elles.
En réalité, une implémentation embarque avec elle des attributs (et si un objet n'a pas d'attribut c'est que le développeur a codé en procédurale "pure", il n'a rien encapsulé, ça n'est pas objet du tout mais je m'égare). Le problème avec les implémentations ce sont justement les attributs qui deviennent visibles. Dit autrement nous commençons à devenir dépendant de la structure de données qui nous arrive et non plus d'un ensemble de fonctions (ie. méthodes) que nous pouvons exécuter. D'ailleurs nous sommes tellement dépendant des attributs que même s'ils sont privés, nous allons alors ajouter des getters/setters pour y accéder quand même.
Remonter à l'interface c'est casser ce lien explicite avec la structure de données embarquée dans une classe et alors un changement de structure ou de structure de la structure n'impactera pas le code utilisateur.
Mais alors quel est le problème avec la programmation fonctionnelle "pure" ?
C'est justement qu'elle pousse tous les morceaux de code à dépendre des mêmes structures. Changez la structure à un endroit et vous êtes partis pour changer toutes les fonctions qui s'appuient sur cette structure. Cela engendre fondamentalement un maillage global de tous les pans de code d'une application avec un couplage fort autour de cette ou de ces structures.
La seule condition pour y remédier c'est d'avoir "la bonne structure du premier coup"... lol quoi... Comment prévoir quelles données (et de quels types) nous arriveront demain ?
À l'inverse, retourner des implémentations d'interface autoboxé dans le type de cette interface (c-à-d. les fameux "messages" de la POO) garanti non seulement que les changements de structures n'auront pas d'impact, mais que les changements d'algorithmes non plus (ici "pas d'impact" est à prendre au sens où le contrat d'interfaçage n'est pas rompu et donc que le code continu de compiler).
Pourquoi est-ce que je vous parle de tout ça ?
À cause Rust et de mes quatre semaines d'immersion intense.
Soyons clair, je trouve que les concepts derrière le langage sont incroyables et ses performances merveilleuses (en tant que dev Java j'ai toujours détesté la JVM rien que pour ce sujet). Par contre le fait que Rust se soit tourné exclusivement vers le fonctionnel et la programmation en "structure-first" à la place de celle en "contract-first" car la majorité des devs ne parviennent pas à penser en objets avec l'encapsulation, cela fait de Rust un langage aussi immaintenable que C mais un peu plus fiable grâce à son meilleur compilateur.
L'API de Rust est digne de celle du C. Par exemple, prenons la méthodes HashMap::keys()de la stdlib de Rust. Celle-ci aurait pu retourner l'implémentation d'un trait Iterator mais non, elle retourne une structure Key qui contient une structureIter qui contient une autre structure base::Iter.
Changez un morceau de la chaîne et préparez-vous à gérer les impacts partout.
En résumé, et après être passée dans l'ordre par Java, OCaml, PHP, C, ASM, Bash, CSH, Python, JavaScript (ES5 à ES7), Anubis, Haskell, Ruby, Groovy, TypeScript, Scala, Go, Kotlin et enfin Rust (ndr. je bidouillais en Rust depuis quelques années), je peux vous assurer que :
- Rust est techniquement un super langage avec l'un des meilleurs compilateur du marché.
- Rust a une API aussi pourrie que celle de C, encourageant le couplage et augmentant l'immaintenabilité. Je crois qu'il doit exister un moyen d'outre-passer cela, mais je ne sais pas encore comment faire et ça me fruste pas mal.
Enfin, je sais que certains dev vont être fâchés de lire ce que j'écris alors permettez-moi de vous proposer un test car j'ai le sentiment que si c'est le cas, c'est que vous n'avez jamais pensé en OOP - et donc que vous ne pouvez pas encore comprendre ce que je dis. Il s'agit d'un exercice que @Kysofer a imaginé pour ses entretiens d'embauche afin de savoir si un candidat "expert Java" savait penser et programmer en orienté objet.
Prenez ces deux classes :
class Person {
private final String name;
private final String firstName;
private final int age;
public Person(String name, String firstName, int age) {
this.name = name;
this.firstName = firstName;
this.age = age;
}
}
class Car {
private final String brand;
private final String name;
public Car(String brand, String name) {
this.brand = brand;
this.name = name;
}
}Objectifs :
- Sans violer l'encapsulation, c'est-à-dire sans jamais accéder aux attributs des deux classes depuis l'extérieur de ces deux classes.
- Sans ajouter des getter ou des setter.
- Sans mettre les attributs en public, package ou protected.
- Sans implémenter les algorithmes de conversion à l'intérieur des deux classes elles-mêmes.
=> Écrivez une architecture qui soit capable de convertir en JSON ou en XML ces deux objets.
Indice : Quand on pense en objet, c'est évident, très facile même. Quand on ne pense qu'en procédurale ou son évolution en fonctionnel, cela paraît impossible.
Et dans tout ça je ne compte pas arrêter Rust pour autant mais je fais appel à mes amis pour qu'ils m'aident à trouver une façon "clean" de coder dans ce langage.
Pour toi @Animal, une explication des méthodologies de gestion des risques.
Je viens de percuter qu'en Rust, les TU sont dans le même fichier que celui du source à tester à ceci près qu'ils sont dans un module appelé tests... J'ai failli vomir sur le coup !
On a quand même bientôt 20 années de Maven et Gradle, ou de Composer et Symfony, ou encore presque une décennie de npm/yarn et Karma, de rake et Ruby, de pyb et Python ; et des gens n'ont toujours pas compris qu'il y avait une différence entre les sources qu'on livre et celles qui servent à fabriquer les sources qui vont être livrées. De la même manière qu'il ne faut pas générer les binaires dans le répertoire ./src il ne faut pas mélanger le code de ses TU avec celui de son programme, idem pour les ressources des tests et du programme.
Il n'y a pas à dire, l'univers des langages bas niveau (C/C++/Rust/Go/etc) est d'une pauvreté en terme de méthodologie, c'est incroyable ! D'autant qu'une bonne partie des personnes y œuvrant se prends systématiquement pour des cadors, j'ai de la peine pour eux et encore plus pour ceux qui doivent faire avec...
Bref, pour des raisons évidentes d'hygiène je vais détourner le répertoire des TI en TU si c'est possible de le faire...
EDIT : l'arborescence standard d'un projet Rust.
.
├── Cargo.lock
├── Cargo.toml
├── src/
│ ├── lib.rs
│ ├── main.rs
│ └── bin/
│ ├── named-executable.rs
│ ├── another-executable.rs
│ └── multi-file-executable/
│ ├── main.rs
│ └── some_module.rs
├── benches/
│ ├── large-input.rs
│ └── multi-file-bench/
│ ├── main.rs
│ └── bench_module.rs
├── examples/
│ ├── simple.rs
│ └── multi-file-example/
│ ├── main.rs
│ └── ex_module.rs
└── tests/
├── some-integration-tests.rs
└── multi-file-test/
├── main.rs
└── test_module.rs
Je viens de trouver l'animé pour toi @Animal :
Tatsuhiro Satô est un hikikomori c'est à dire une personne qui préfère rester enfermée chez elle plutôt que de vivre en société. Cela fait déjà trois ans qu'il est resté enfermé chez lui à réfléchir et il en est arrivé à la conclusion que sa situation est dû à un complot de la NHK (chaîne de tv japonaise) afin de créer plein d'hikikomori. Il décide alors de lutter contre cette conspiration et de sortir de chez lui mais c'est pas toujours facile pour un hikikomori.
... Message... :)
MERCI ! Je suis en train de me battre chez mon client actuel pour pousser du no-estimate. Je leur avais sorti plein de façons d'estimer à moindre frais en m'appuyant sur le contenu des conférences de @Chlouchloutte, notamment celle portant sur la Sociologie du Management et l'autre sur l'Historique de la Structuration des Organisations.
J'en étais même venue à faire de la fouloscopie et imaginer avec @Kysofer des techniques d'estimation par intelligence collective (comme l'explique Mehdi Moussaid dans l'une de ses conférences) et pourtant impossible de faire changer d'avis les décideurs : il faut estimer et estimer précis !
Ce qui m'intéresse dans cette étude c'est qu'à 61%, et quelque soit le degré d'expérience, les estimations seraient fausses. C'est un argument de poids pour moi !
Merci encore une fois Chezsoi pour le lien.
Sur une idée de @Kysofer, je reprends mon post précédent pour mettre à jour l'exemple que j'avais donné afin de l'améliorer et de le simplifier.
L'idée est de se débarrasser des méthodes 'static' de chaque structure que j'avais appelées "new" pour les remplacer par des fonctions globales (globales au niveau du module) à côté des structures et dont le nom est plus porteur de sens. (ndr. elles remplacent les constructeurs nommés de Yegor Bugayenko en prenant un petit peu de la Factory Method défendue par Joshua Bloch).
L'intérêt des d'avoir des objets concrets qui profitent tout de suite du polymorphisme d'une interface (ici "Addition") et de wrapper ces instances dans une Box<dyn T> pour être réutilisées ailleurs, y compris dans une struct. Cela découple totalement les liens entres les instances puisque seules les types des interfaces fuitent.
Si à cela on ajoute l'immutabilité totale et l'absence de getter/setter, alors cela commence à être du vrai FOP (Functional-Object Programming) dont la base s'appuie sur la notion d'Elegant Objects.
Je suis contente de savoir à présent allier parfaitement paradigmes fonctionnel et objet alors qu'ils m'ont toujours été présentés comme deux antagonistes.
L'étape suivante sera de compléter l'exemple pour effectuer le même calcul en multi-thread et tirer 100% de la puissance de Rust. @Kysofer, si tu as l'envie de m'aider :P
#![allow(non_snake_case)]
// Exécution
fn main() {
let additionA = AdditionFromCouple(1, 2);
println!("Couple add : [{}]", additionA.add()); // Print 3
// Ne pas oublier de wrapper Couple dans une Box
let additionB = AdditionFromTriplet(additionA, 3);
println!("Triplet add : [{}]", additionB.add()); // Print 6
}
// Traits
trait Addition {
fn add(&self) -> i32;
}
// Structures
struct Couple {
opA: i32,
opB: i32,
}
struct Triplet {
opA: Box<dyn Addition>,
opB: i32,
}
// Implémentations
impl Addition for Couple {
fn add(&self) -> i32 {
return self.opA + self.opB;
}
}
impl Addition for Triplet {
fn add(&self) -> i32 {
return (*self.opA).add() + self.opB;
}
}
// Factory Methods (Utilisées comme constructeurs)
fn AdditionFromCouple(opA: i32, opB: i32) -> Box<dyn Addition> {
return Box::new(Couple { opA: opA, opB: opB });
}
fn AdditionFromTriplet(opA: Box<dyn Addition>, opB: i32) -> Box<dyn Addition> {
return Box::new(Triplet { opA: opA, opB: opB });
}