Struct prefix_trie::map::VacantEntry

pub struct VacantEntry<'a, P, T> { /* private fields */ }

A mutable view into a missing entry. The information within this structure describes a path towards that missing node, and how to insert it.

Implementations

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

pub fn key(&self) -> &P

Gets a reference to the key in the entry.

use prefix_trie::map::Entry;
let mut pm: PrefixMap<Ipv4Net, i32> = PrefixMap::new();
match pm.entry("192.168.1.0/24".parse()?) {
    Entry::Vacant(e) => assert_eq!(e.key(), &"192.168.1.0/24".parse()?),
    Entry::Occupied(_) => unreachable!(),
}

impl<'a, P, T> VacantEntry<'a, P, T>where
    P: Prefix,

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

Get a mutable reference to the value. If the value is yet empty, set it to the given default value.

use prefix_trie::map::Entry;
let mut pm: PrefixMap<Ipv4Net, i32> = PrefixMap::new();
match pm.entry("192.168.1.0/24".parse()?) {
    Entry::Vacant(mut e) => assert_eq!(e.insert(10), &10),
    Entry::Occupied(_) => unreachable!(),
}
assert_eq!(pm.get(&"192.168.1.0/24".parse()?), Some(&10));

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

Get a mutable reference to the value. If the value is yet empty, set it to the return value from the given function.

use prefix_trie::map::Entry;
let mut pm: PrefixMap<Ipv4Net, i32> = PrefixMap::new();
match pm.entry("192.168.1.0/24".parse()?) {
    Entry::Vacant(mut e) => assert_eq!(e.insert_with(|| 10), &10),
    Entry::Occupied(_) => unreachable!(),
}
assert_eq!(pm.get(&"192.168.1.0/24".parse()?), Some(&10));

impl<'a, P, T> VacantEntry<'a, P, T>where
    P: Prefix,
    T: Default,

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

Get a mutable reference to the value. If the value is yet empty, set it to the default value using Default::default().

use prefix_trie::map::Entry;
let mut pm: PrefixMap<Ipv4Net, i32> = PrefixMap::new();
match pm.entry("192.168.1.0/24".parse()?) {
    Entry::Vacant(e) => assert_eq!(e.default(), &0),
    Entry::Occupied(_) => unreachable!(),
}
assert_eq!(pm.get(&"192.168.1.0/24".parse()?), Some(&0));