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Rollup merge of #77851 - exrook:split-btreemap, r=dtolnay

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BTreeMap: refactor Entry out of map.rs into its own file

btree/map.rs is approaching the 3000 line mark, splitting out the entry
code buys about 500 lines of headroom.

I've created this PR because the changes I've made in #77438 will push `map.rs` over the 3000 line limit and cause tidy to complain.

I picked `Entry` to factor out because it feels less tightly coupled to the rest of `BTreeMap` than the various iterator implementations.

Related: #60302
This commit is contained in:
Yuki Okushi 2020-10-18 04:11:07 +09:00 committed by GitHub
commit a0242e73bb
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3 changed files with 481 additions and 469 deletions
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473
library/alloc/src/collections/btree/map.rs
View File

@ -9,13 +9,16 @@ use core::ops::{Index, RangeBounds};
use core::ptr;
use super::borrow::DormantMutRef;
use super::node::{self, marker, ForceResult::*, Handle, InsertResult::*, NodeRef};
use super::node::{self, marker, ForceResult::*, Handle, NodeRef};
use super::search::{self, SearchResult::*};
use super::unwrap_unchecked;
use Entry::*;
use UnderflowResult::*;
mod entry;
pub use entry::{Entry, OccupiedEntry, VacantEntry};
use Entry::*;
/// A map based on a B-Tree.
///
/// B-Trees represent a fundamental compromise between cache-efficiency and actually minimizing
@ -452,69 +455,6 @@ impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for RangeMut<'_, K, V> {
}
}
/// 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 [`BTreeMap`].
///
/// [`entry`]: BTreeMap::entry
#[stable(feature = "rust1", since = "1.0.0")]
pub enum Entry<'a, K: 'a, V: 'a> {
/// A vacant entry.
#[stable(feature = "rust1", since = "1.0.0")]
Vacant(#[stable(feature = "rust1", since = "1.0.0")] VacantEntry<'a, K, V>),
/// An occupied entry.
#[stable(feature = "rust1", since = "1.0.0")]
Occupied(#[stable(feature = "rust1", since = "1.0.0")] OccupiedEntry<'a, K, V>),
}
#[stable(feature = "debug_btree_map", since = "1.12.0")]
impl<K: Debug + Ord, 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 a vacant entry in a `BTreeMap`.
/// It is part of the [`Entry`] enum.
#[stable(feature = "rust1", since = "1.0.0")]
pub struct VacantEntry<'a, K: 'a, V: 'a> {
key: K,
handle: Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, marker::Edge>,
dormant_map: DormantMutRef<'a, BTreeMap<K, V>>,
// Be invariant in `K` and `V`
_marker: PhantomData<&'a mut (K, V)>,
}
#[stable(feature = "debug_btree_map", since = "1.12.0")]
impl<K: Debug + Ord, V> Debug for VacantEntry<'_, K, V> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_tuple("VacantEntry").field(self.key()).finish()
}
}
/// A view into an occupied entry in a `BTreeMap`.
/// It is part of the [`Entry`] enum.
#[stable(feature = "rust1", since = "1.0.0")]
pub struct OccupiedEntry<'a, K: 'a, V: 'a> {
handle: Handle<NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal>, marker::KV>,
dormant_map: DormantMutRef<'a, BTreeMap<K, V>>,
// Be invariant in `K` and `V`
_marker: PhantomData<&'a mut (K, V)>,
}
#[stable(feature = "debug_btree_map", since = "1.12.0")]
impl<K: Debug + Ord, 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()
}
}
// An iterator for merging two sorted sequences into one
struct MergeIter<K, V, I: Iterator<Item = (K, V)>> {
left: Peekable<I>,
@ -2310,409 +2250,6 @@ impl<K, V> BTreeMap<K, V> {
}
}
impl<'a, K: Ord, V> Entry<'a, K, V> {
/// 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::BTreeMap;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
/// map.entry("poneyland").or_insert(12);
///
/// assert_eq!(map["poneyland"], 12);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn or_insert(self, default: V) -> &'a mut V {
match self {
Occupied(entry) => entry.into_mut(),
Vacant(entry) => entry.insert(default),
}
}
/// 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::BTreeMap;
///
/// let mut map: BTreeMap<&str, String> = BTreeMap::new();
/// let s = "hoho".to_string();
///
/// map.entry("poneyland").or_insert_with(|| s);
///
/// assert_eq!(map["poneyland"], "hoho".to_string());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
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()),
}
}
#[unstable(feature = "or_insert_with_key", issue = "71024")]
/// Ensures a value is in the entry by inserting, if empty, the result of the default function,
/// which takes the key as its argument, and returns a mutable reference to the value in the
/// entry.
///
/// # Examples
///
/// ```
/// #![feature(or_insert_with_key)]
/// use std::collections::BTreeMap;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
///
/// map.entry("poneyland").or_insert_with_key(|key| key.chars().count());
///
/// assert_eq!(map["poneyland"], 9);
/// ```
#[inline]
pub fn or_insert_with_key<F: FnOnce(&K) -> V>(self, default: F) -> &'a mut V {
match self {
Occupied(entry) => entry.into_mut(),
Vacant(entry) => {
let value = default(entry.key());
entry.insert(value)
}
}
}
/// Returns a reference to this entry's key.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
/// assert_eq!(map.entry("poneyland").key(), &"poneyland");
/// ```
#[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::BTreeMap;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::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);
/// ```
#[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),
}
}
}
impl<'a, K: Ord, 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
///
/// ```
/// use std::collections::BTreeMap;
///
/// let mut map: BTreeMap<&str, Option<usize>> = BTreeMap::new();
/// map.entry("poneyland").or_default();
///
/// assert_eq!(map["poneyland"], None);
/// ```
pub fn or_default(self) -> &'a mut V {
match self {
Occupied(entry) => entry.into_mut(),
Vacant(entry) => entry.insert(Default::default()),
}
}
}
impl<'a, K: Ord, V> 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::BTreeMap;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
/// assert_eq!(map.entry("poneyland").key(), &"poneyland");
/// ```
#[stable(feature = "map_entry_keys", since = "1.10.0")]
pub fn key(&self) -> &K {
&self.key
}
/// Take ownership of the key.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
///
/// if let Entry::Vacant(v) = map.entry("poneyland") {
/// v.into_key();
/// }
/// ```
#[stable(feature = "map_entry_recover_keys2", since = "1.12.0")]
pub fn into_key(self) -> K {
self.key
}
/// Sets the value of the entry with the `VacantEntry`'s key,
/// and returns a mutable reference to it.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, u32> = BTreeMap::new();
///
/// if let Entry::Vacant(o) = map.entry("poneyland") {
/// o.insert(37);
/// }
/// assert_eq!(map["poneyland"], 37);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn insert(self, value: V) -> &'a mut V {
let out_ptr = match self.handle.insert_recursing(self.key, value) {
(Fit(_), val_ptr) => {
// Safety: We have consumed self.handle and the handle returned.
let map = unsafe { self.dormant_map.awaken() };
map.length += 1;
val_ptr
}
(Split(ins), val_ptr) => {
drop(ins.left);
// Safety: We have consumed self.handle and the reference returned.
let map = unsafe { self.dormant_map.awaken() };
let root = map.root.as_mut().unwrap();
root.push_internal_level().push(ins.k, ins.v, ins.right);
map.length += 1;
val_ptr
}
};
// Now that we have finished growing the tree using borrowed references,
// dereference the pointer to a part of it, that we picked up along the way.
unsafe { &mut *out_ptr }
}
}
impl<'a, K: Ord, V> OccupiedEntry<'a, K, V> {
/// Gets a reference to the key in the entry.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
/// map.entry("poneyland").or_insert(12);
/// assert_eq!(map.entry("poneyland").key(), &"poneyland");
/// ```
#[stable(feature = "map_entry_keys", since = "1.10.0")]
pub fn key(&self) -> &K {
self.handle.reborrow().into_kv().0
}
/// Take ownership of the key and value from the map.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::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();
/// }
///
/// // If now try to get the value, it will panic:
/// // println!("{}", map["poneyland"]);
/// ```
#[stable(feature = "map_entry_recover_keys2", since = "1.12.0")]
pub fn remove_entry(self) -> (K, V) {
self.remove_kv()
}
/// Gets a reference to the value in the entry.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
/// map.entry("poneyland").or_insert(12);
///
/// if let Entry::Occupied(o) = map.entry("poneyland") {
/// assert_eq!(o.get(), &12);
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn get(&self) -> &V {
self.handle.reborrow().into_kv().1
}
/// Gets a mutable reference to the value in the entry.
///
/// If you need a reference to the `OccupiedEntry` that may outlive the
/// destruction of the `Entry` value, see [`into_mut`].
///
/// [`into_mut`]: OccupiedEntry::into_mut
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::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);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn get_mut(&mut self) -> &mut V {
self.handle.kv_mut().1
}
/// Converts the entry into a mutable reference to its value.
///
/// If you need multiple references to the `OccupiedEntry`, see [`get_mut`].
///
/// [`get_mut`]: OccupiedEntry::get_mut
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::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);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn into_mut(self) -> &'a mut V {
self.handle.into_val_mut()
}
/// Sets the value of the entry with the `OccupiedEntry`'s key,
/// and returns the entry's old value.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::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);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn insert(&mut self, value: V) -> V {
mem::replace(self.get_mut(), value)
}
/// Takes the value of the entry out of the map, and returns it.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
/// map.entry("poneyland").or_insert(12);
///
/// if let Entry::Occupied(o) = map.entry("poneyland") {
/// assert_eq!(o.remove(), 12);
/// }
/// // If we try to get "poneyland"'s value, it'll panic:
/// // println!("{}", map["poneyland"]);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn remove(self) -> V {
self.remove_kv().1
}
// Body of `remove_entry`, separate to keep the above implementations short.
fn remove_kv(self) -> (K, V) {
let mut emptied_internal_root = false;
let (old_kv, _) = self.handle.remove_kv_tracking(|| emptied_internal_root = true);
// SAFETY: we consumed the intermediate root borrow, `self.handle`.
let map = unsafe { self.dormant_map.awaken() };
map.length -= 1;
if emptied_internal_root {
let root = map.root.as_mut().unwrap();
root.pop_internal_level();
}
old_kv
}
}
impl<'a, K: 'a, V: 'a> Handle<NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal>, marker::KV> {
/// Removes a key/value-pair from the map, and returns that pair, as well as
/// the leaf edge corresponding to that former pair.

475
library/alloc/src/collections/btree/map/entry.rs Normal file
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@ -0,0 +1,475 @@
use core::fmt::{self, Debug};
use core::marker::PhantomData;
use core::mem;
use super::super::borrow::DormantMutRef;
use super::super::node::{marker, Handle, InsertResult::*, NodeRef};
use super::BTreeMap;
use Entry::*;
/// 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 [`BTreeMap`].
///
/// [`entry`]: BTreeMap::entry
#[stable(feature = "rust1", since = "1.0.0")]
pub enum Entry<'a, K: 'a, V: 'a> {
/// A vacant entry.
#[stable(feature = "rust1", since = "1.0.0")]
Vacant(#[stable(feature = "rust1", since = "1.0.0")] VacantEntry<'a, K, V>),
/// An occupied entry.
#[stable(feature = "rust1", since = "1.0.0")]
Occupied(#[stable(feature = "rust1", since = "1.0.0")] OccupiedEntry<'a, K, V>),
}
#[stable(feature = "debug_btree_map", since = "1.12.0")]
impl<K: Debug + Ord, 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 a vacant entry in a `BTreeMap`.
/// It is part of the [`Entry`] enum.
#[stable(feature = "rust1", since = "1.0.0")]
pub struct VacantEntry<'a, K: 'a, V: 'a> {
pub(super) key: K,
pub(super) handle: Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, marker::Edge>,
pub(super) dormant_map: DormantMutRef<'a, BTreeMap<K, V>>,
// Be invariant in `K` and `V`
pub(super) _marker: PhantomData<&'a mut (K, V)>,
}
#[stable(feature = "debug_btree_map", since = "1.12.0")]
impl<K: Debug + Ord, V> Debug for VacantEntry<'_, K, V> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_tuple("VacantEntry").field(self.key()).finish()
}
}
/// A view into an occupied entry in a `BTreeMap`.
/// It is part of the [`Entry`] enum.
#[stable(feature = "rust1", since = "1.0.0")]
pub struct OccupiedEntry<'a, K: 'a, V: 'a> {
pub(super) handle: Handle<NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal>, marker::KV>,
pub(super) dormant_map: DormantMutRef<'a, BTreeMap<K, V>>,
// Be invariant in `K` and `V`
pub(super) _marker: PhantomData<&'a mut (K, V)>,
}
#[stable(feature = "debug_btree_map", since = "1.12.0")]
impl<K: Debug + Ord, 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()
}
}
impl<'a, K: Ord, V> Entry<'a, K, V> {
/// 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::BTreeMap;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
/// map.entry("poneyland").or_insert(12);
///
/// assert_eq!(map["poneyland"], 12);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn or_insert(self, default: V) -> &'a mut V {
match self {
Occupied(entry) => entry.into_mut(),
Vacant(entry) => entry.insert(default),
}
}
/// 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::BTreeMap;
///
/// let mut map: BTreeMap<&str, String> = BTreeMap::new();
/// let s = "hoho".to_string();
///
/// map.entry("poneyland").or_insert_with(|| s);
///
/// assert_eq!(map["poneyland"], "hoho".to_string());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
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()),
}
}
#[unstable(feature = "or_insert_with_key", issue = "71024")]
/// Ensures a value is in the entry by inserting, if empty, the result of the default function,
/// which takes the key as its argument, and returns a mutable reference to the value in the
/// entry.
///
/// # Examples
///
/// ```
/// #![feature(or_insert_with_key)]
/// use std::collections::BTreeMap;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
///
/// map.entry("poneyland").or_insert_with_key(|key| key.chars().count());
///
/// assert_eq!(map["poneyland"], 9);
/// ```
#[inline]
pub fn or_insert_with_key<F: FnOnce(&K) -> V>(self, default: F) -> &'a mut V {
match self {
Occupied(entry) => entry.into_mut(),
Vacant(entry) => {
let value = default(entry.key());
entry.insert(value)
}
}
}
/// Returns a reference to this entry's key.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
/// assert_eq!(map.entry("poneyland").key(), &"poneyland");
/// ```
#[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::BTreeMap;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::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);
/// ```
#[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),
}
}
}
impl<'a, K: Ord, 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
///
/// ```
/// use std::collections::BTreeMap;
///
/// let mut map: BTreeMap<&str, Option<usize>> = BTreeMap::new();
/// map.entry("poneyland").or_default();
///
/// assert_eq!(map["poneyland"], None);
/// ```
pub fn or_default(self) -> &'a mut V {
match self {
Occupied(entry) => entry.into_mut(),
Vacant(entry) => entry.insert(Default::default()),
}
}
}
impl<'a, K: Ord, V> 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::BTreeMap;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
/// assert_eq!(map.entry("poneyland").key(), &"poneyland");
/// ```
#[stable(feature = "map_entry_keys", since = "1.10.0")]
pub fn key(&self) -> &K {
&self.key
}
/// Take ownership of the key.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
///
/// if let Entry::Vacant(v) = map.entry("poneyland") {
/// v.into_key();
/// }
/// ```
#[stable(feature = "map_entry_recover_keys2", since = "1.12.0")]
pub fn into_key(self) -> K {
self.key
}
/// Sets the value of the entry with the `VacantEntry`'s key,
/// and returns a mutable reference to it.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, u32> = BTreeMap::new();
///
/// if let Entry::Vacant(o) = map.entry("poneyland") {
/// o.insert(37);
/// }
/// assert_eq!(map["poneyland"], 37);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn insert(self, value: V) -> &'a mut V {
let out_ptr = match self.handle.insert_recursing(self.key, value) {
(Fit(_), val_ptr) => {
// Safety: We have consumed self.handle and the handle returned.
let map = unsafe { self.dormant_map.awaken() };
map.length += 1;
val_ptr
}
(Split(ins), val_ptr) => {
drop(ins.left);
// Safety: We have consumed self.handle and the reference returned.
let map = unsafe { self.dormant_map.awaken() };
let root = map.root.as_mut().unwrap();
root.push_internal_level().push(ins.k, ins.v, ins.right);
map.length += 1;
val_ptr
}
};
// Now that we have finished growing the tree using borrowed references,
// dereference the pointer to a part of it, that we picked up along the way.
unsafe { &mut *out_ptr }
}
}
impl<'a, K: Ord, V> OccupiedEntry<'a, K, V> {
/// Gets a reference to the key in the entry.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
/// map.entry("poneyland").or_insert(12);
/// assert_eq!(map.entry("poneyland").key(), &"poneyland");
/// ```
#[stable(feature = "map_entry_keys", since = "1.10.0")]
pub fn key(&self) -> &K {
self.handle.reborrow().into_kv().0
}
/// Take ownership of the key and value from the map.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::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();
/// }
///
/// // If now try to get the value, it will panic:
/// // println!("{}", map["poneyland"]);
/// ```
#[stable(feature = "map_entry_recover_keys2", since = "1.12.0")]
pub fn remove_entry(self) -> (K, V) {
self.remove_kv()
}
/// Gets a reference to the value in the entry.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
/// map.entry("poneyland").or_insert(12);
///
/// if let Entry::Occupied(o) = map.entry("poneyland") {
/// assert_eq!(o.get(), &12);
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn get(&self) -> &V {
self.handle.reborrow().into_kv().1
}
/// Gets a mutable reference to the value in the entry.
///
/// If you need a reference to the `OccupiedEntry` that may outlive the
/// destruction of the `Entry` value, see [`into_mut`].
///
/// [`into_mut`]: OccupiedEntry::into_mut
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::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);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn get_mut(&mut self) -> &mut V {
self.handle.kv_mut().1
}
/// Converts the entry into a mutable reference to its value.
///
/// If you need multiple references to the `OccupiedEntry`, see [`get_mut`].
///
/// [`get_mut`]: OccupiedEntry::get_mut
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::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);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn into_mut(self) -> &'a mut V {
self.handle.into_val_mut()
}
/// Sets the value of the entry with the `OccupiedEntry`'s key,
/// and returns the entry's old value.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::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);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn insert(&mut self, value: V) -> V {
mem::replace(self.get_mut(), value)
}
/// Takes the value of the entry out of the map, and returns it.
///
/// # Examples
///
/// ```
/// use std::collections::BTreeMap;
/// use std::collections::btree_map::Entry;
///
/// let mut map: BTreeMap<&str, usize> = BTreeMap::new();
/// map.entry("poneyland").or_insert(12);
///
/// if let Entry::Occupied(o) = map.entry("poneyland") {
/// assert_eq!(o.remove(), 12);
/// }
/// // If we try to get "poneyland"'s value, it'll panic:
/// // println!("{}", map["poneyland"]);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn remove(self) -> V {
self.remove_kv().1
}
// Body of `remove_entry`, separate to keep the above implementations short.
pub(super) fn remove_kv(self) -> (K, V) {
let mut emptied_internal_root = false;
let (old_kv, _) = self.handle.remove_kv_tracking(|| emptied_internal_root = true);
// SAFETY: we consumed the intermediate root borrow, `self.handle`.
let map = unsafe { self.dormant_map.awaken() };
map.length -= 1;
if emptied_internal_root {
let root = map.root.as_mut().unwrap();
root.pop_internal_level();
}
old_kv
}
}

2
src/tools/clippy/clippy_lints/src/utils/paths.rs
View File

@ -14,7 +14,7 @@ pub const BINARY_HEAP: [&str; 4] = ["alloc", "collections", "binary_heap", "Bina
pub const BORROW_TRAIT: [&str; 3] = ["core", "borrow", "Borrow"];
pub const BOX: [&str; 3] = ["alloc", "boxed", "Box"];
pub const BTREEMAP: [&str; 5] = ["alloc", "collections", "btree", "map", "BTreeMap"];
pub const BTREEMAP_ENTRY: [&str; 5] = ["alloc", "collections", "btree", "map", "Entry"];
pub const BTREEMAP_ENTRY: [&str; 6] = ["alloc", "collections", "btree", "map", "entry", "Entry"];
pub const BTREESET: [&str; 5] = ["alloc", "collections", "btree", "set", "BTreeSet"];
pub const CLONE_TRAIT: [&str; 3] = ["core", "clone", "Clone"];
pub const CLONE_TRAIT_METHOD: [&str; 4] = ["core", "clone", "Clone", "clone"];