Enum `Entry`

enum Entry<'a>

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 Map.

Variants

Vacant(VacantEntry<'a>): A vacant Entry.
Occupied(OccupiedEntry<'a>): An occupied Entry.

Implementations

`impl<'a> Entry<'a>`

fn key(self: &Self) -> &String

Returns a reference to this entry's key.

Examples

let mut map = serde_json::Map::new();
assert_eq!(map.entry("serde").key(), &"serde");

fn or_insert(self: Self, default: Value) -> &'a mut Value

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 serde_json::json;
#
let mut map = serde_json::Map::new();
map.entry("serde").or_insert(json!(12));

assert_eq!(map["serde"], 12);

fn or_insert_with<F>(self: Self, default: F) -> &'a mut Value where F: FnOnce() -> Value

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 serde_json::json;
#
let mut map = serde_json::Map::new();
map.entry("serde").or_insert_with(|| json!("hoho"));

assert_eq!(map["serde"], "hoho".to_owned());

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

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

Examples

# use serde_json::json;
#
let mut map = serde_json::Map::new();
map.entry("serde")
    .and_modify(|e| *e = json!("rust"))
    .or_insert(json!("cpp"));

assert_eq!(map["serde"], "cpp");

map.entry("serde")
    .and_modify(|e| *e = json!("rust"))
    .or_insert(json!("cpp"));

assert_eq!(map["serde"], "rust");

`impl<'a> Freeze for Entry<'a>`

`impl<'a> RefUnwindSafe for Entry<'a>`

`impl<'a> Send for Entry<'a>`

`impl<'a> Sync for Entry<'a>`

`impl<'a> Unpin for Entry<'a>`

`impl<'a> UnwindSafe for Entry<'a>`

`impl<T> Any for Entry<'a>`

fn type_id(self: &Self) -> TypeId

`impl<T> Borrow for Entry<'a>`

fn borrow(self: &Self) -> &T

`impl<T> BorrowMut for Entry<'a>`

fn borrow_mut(self: &mut Self) -> &mut T

`impl<T> From for Entry<'a>`

fn from(t: T) -> T: Returns the argument unchanged.

`impl<T, U> Into for Entry<'a>`

fn into(self: Self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of [From]<T> for U chooses to do.

`impl<T, U> TryFrom for Entry<'a>`

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

`impl<T, U> TryInto for Entry<'a>`

fn try_into(self: Self) -> Result<U, <U as TryFrom<T>>::Error>