Enum Entry

pub enum Entry<'a, P, T> {
    Vacant(VacantEntry<'a, P, T>),
    Occupied(OccupiedEntry<'a, P, T>),
}

A mutable view into a single entry in a map, which may either be vacant or occupied.

Variants

Vacant(VacantEntry<'a, P, T>)

The entry is not present in the tree.

Occupied(OccupiedEntry<'a, P, T>)

The entry is already present in the tree.

Implementations

impl<P, T> Entry<'_, P, T>

pub fn get(&self) -> Option<&T>

Get the value if it exists

let mut pm: PrefixMap<ipnet::Ipv4Net, _> = PrefixMap::new();
pm.insert("192.168.1.0/24".parse()?, 1);
assert_eq!(pm.entry("192.168.1.0/24".parse()?).get(), Some(&1));
assert_eq!(pm.entry("192.168.2.0/24".parse()?).get(), None);

pub fn get_mut(&mut self) -> Option<&mut T>

Get the value if it exists

let mut pm: PrefixMap<ipnet::Ipv4Net, _> = PrefixMap::new();
pm.insert("192.168.1.0/24".parse()?, 1);
pm.entry("192.168.1.0/24".parse()?).get_mut().map(|x| *x += 1);
pm.entry("192.168.2.0/24".parse()?).get_mut().map(|x| *x += 1);
assert_eq!(pm.get(&"192.168.1.0/24".parse()?), Some(&2));
assert_eq!(pm.get(&"192.168.2.0/24".parse()?), None);

pub fn key(&self) -> &P

get the key of the current entry

let mut pm: PrefixMap<ipnet::Ipv4Net, _> = PrefixMap::new();
pm.insert("192.168.1.0/24".parse()?, 1);
assert_eq!(pm.entry("192.168.1.0/24".parse()?).key(), &"192.168.1.0/24".parse()?);
assert_eq!(pm.entry("192.168.2.0/24".parse()?).key(), &"192.168.2.0/24".parse()?);

impl<'a, P, T> Entry<'a, P, T>

where P: Prefix,

pub fn insert(self, v: T) -> Option<T>

Replace the current entry, and return the entry that was stored before. This will also replace the key with the one provided to the entry function.

let mut pm: PrefixMap<ipnet::Ipv4Net, _> = PrefixMap::new();
pm.insert("192.168.1.0/24".parse()?, 1);

assert_eq!(pm.entry("192.168.1.0/24".parse()?).insert(10), Some(1));
assert_eq!(pm.entry("192.168.2.0/24".parse()?).insert(20), None);

assert_eq!(pm.get(&"192.168.1.0/24".parse()?), Some(&10));
assert_eq!(pm.get(&"192.168.2.0/24".parse()?), Some(&20));

This function will replace the prefix in the map with the one provided to the entry call:

let mut pm: PrefixMap<ipnet::Ipv4Net, _> = PrefixMap::new();
pm.insert("192.168.1.1/24".parse()?, 1);
pm.entry("192.168.1.2/24".parse()?).insert(2);
assert_eq!(
    pm.get_key_value(&"192.168.1.0/24".parse()?),
    Some((&"192.168.1.2/24".parse()?, &2)) // prefix is overwritten
);

pub fn or_insert(self, default: T) -> &'a mut T

Ensures a value is in the entry by inserting the default if empty, and returns a mutable reference to the value in the entry.

let mut pm: PrefixMap<ipnet::Ipv4Net, _> = PrefixMap::new();
pm.insert("192.168.1.0/24".parse()?, 1);

assert_eq!(pm.entry("192.168.1.0/24".parse()?).or_insert(10), &1);
assert_eq!(pm.entry("192.168.2.0/24".parse()?).or_insert(20), &20);

assert_eq!(pm.get(&"192.168.1.0/24".parse()?), Some(&1));
assert_eq!(pm.get(&"192.168.2.0/24".parse()?), Some(&20));

This function will not replace the prefix in the map if it already exists.

let mut pm: PrefixMap<ipnet::Ipv4Net, _> = PrefixMap::new();
pm.insert("192.168.1.1/24".parse()?, 1);
pm.entry("192.168.1.2/24".parse()?).or_insert(2);
assert_eq!(
    pm.get_key_value(&"192.168.1.0/24".parse()?),
    Some((&"192.168.1.1/24".parse()?, &1)) // prefix is not overwritten.
);

pub fn or_insert_with<F: FnOnce() -> T>(self, default: F) -> &'a mut T

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.

let mut pm: PrefixMap<ipnet::Ipv4Net, _> = PrefixMap::new();
pm.insert("192.168.1.0/24".parse()?, 1);

assert_eq!(pm.entry("192.168.1.0/24".parse()?).or_insert_with(|| 10), &1);
assert_eq!(pm.entry("192.168.2.0/24".parse()?).or_insert_with(|| 20), &20);

assert_eq!(pm.get(&"192.168.1.0/24".parse()?), Some(&1));
assert_eq!(pm.get(&"192.168.2.0/24".parse()?), Some(&20));

This function will not replace the prefix in the map if it already exists.

let mut pm: PrefixMap<ipnet::Ipv4Net, _> = PrefixMap::new();
pm.insert("192.168.1.1/24".parse()?, 1);
pm.entry("192.168.1.2/24".parse()?).or_insert_with(|| 2);
assert_eq!(
    pm.get_key_value(&"192.168.1.0/24".parse()?),
    Some((&"192.168.1.1/24".parse()?, &1)) // prefix is not overwritten.
);

pub fn and_modify<F: FnOnce(&mut T)>(self, f: F) -> Self

Provides in-place mutable access to an occupied entry before any potential inserts into the map.

let mut pm: PrefixMap<ipnet::Ipv4Net, _> = PrefixMap::new();
pm.insert("192.168.1.0/24".parse()?, 1);
assert_eq!(pm.entry("192.168.1.0/24".parse()?).and_modify(|x| *x += 1).get(), Some(&2));
assert_eq!(pm.entry("192.168.2.0/24".parse()?).and_modify(|x| *x += 1).get(), None);

This function will not replace the prefix in the map if it already exists.

let mut pm: PrefixMap<ipnet::Ipv4Net, _> = PrefixMap::new();
pm.insert("192.168.1.1/24".parse()?, 1);
pm.entry("192.168.1.2/24".parse()?).and_modify(|x| *x += 1);
assert_eq!(
    pm.get_key_value(&"192.168.1.0/24".parse()?),
    Some((&"192.168.1.1/24".parse()?, &2)) // prefix is not overwritten.
);

impl<'a, P, T> Entry<'a, P, T>

where P: Prefix, T: Default,

pub fn or_default(self) -> &'a mut T

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.

let mut pm: PrefixMap<ipnet::Ipv4Net, _> = PrefixMap::new();
pm.insert("192.168.1.0/24".parse()?, 1);

assert_eq!(pm.entry("192.168.1.0/24".parse()?).or_default(), &1);
assert_eq!(pm.entry("192.168.2.0/24".parse()?).or_default(), &0);

assert_eq!(pm.get(&"192.168.1.0/24".parse()?), Some(&1));
assert_eq!(pm.get(&"192.168.2.0/24".parse()?), Some(&0));

This function will not replace the prefix in the map if it already exists.

let mut pm: PrefixMap<ipnet::Ipv4Net, _> = PrefixMap::new();
pm.insert("192.168.1.1/24".parse()?, 1);
pm.entry("192.168.1.2/24".parse()?).or_default();
assert_eq!(
    pm.get_key_value(&"192.168.1.0/24".parse()?),
    Some((&"192.168.1.1/24".parse()?, &1)) // prefix is not overwritten.
);