Struct serde_json::map::OccupiedEntry

pub struct OccupiedEntry<'a> { /* private fields */ }

An occupied Entry. It is part of the Entry enum.

Implementations

impl<'a> OccupiedEntry<'a>

pub fn key(&self) -> &String

Gets a reference to the key in the entry.

Examples

use serde_json::map::Entry;

let mut map = serde_json::Map::new();
map.insert("serde".to_owned(), json!(12));

match map.entry("serde") {
    Entry::Occupied(occupied) => {
        assert_eq!(occupied.key(), &"serde");
    }
    Entry::Vacant(_) => unimplemented!(),
}

pub fn get(&self) -> &Value

Gets a reference to the value in the entry.

Examples

use serde_json::map::Entry;

let mut map = serde_json::Map::new();
map.insert("serde".to_owned(), json!(12));

match map.entry("serde") {
    Entry::Occupied(occupied) => {
        assert_eq!(occupied.get(), 12);
    }
    Entry::Vacant(_) => unimplemented!(),
}

pub fn get_mut(&mut self) -> &mut Value

Gets a mutable reference to the value in the entry.

Examples

use serde_json::map::Entry;

let mut map = serde_json::Map::new();
map.insert("serde".to_owned(), json!([1, 2, 3]));

match map.entry("serde") {
    Entry::Occupied(mut occupied) => {
        occupied.get_mut().as_array_mut().unwrap().push(json!(4));
    }
    Entry::Vacant(_) => unimplemented!(),
}

assert_eq!(map["serde"].as_array().unwrap().len(), 4);

pub fn into_mut(self) -> &'a mut Value

Converts the entry into a mutable reference to its value.

Examples

use serde_json::map::Entry;

let mut map = serde_json::Map::new();
map.insert("serde".to_owned(), json!([1, 2, 3]));

match map.entry("serde") {
    Entry::Occupied(mut occupied) => {
        occupied.into_mut().as_array_mut().unwrap().push(json!(4));
    }
    Entry::Vacant(_) => unimplemented!(),
}

assert_eq!(map["serde"].as_array().unwrap().len(), 4);

pub fn insert(&mut self, value: Value) -> Value

Sets the value of the entry with the OccupiedEntry’s key, and returns the entry’s old value.

Examples

use serde_json::map::Entry;

let mut map = serde_json::Map::new();
map.insert("serde".to_owned(), json!(12));

match map.entry("serde") {
    Entry::Occupied(mut occupied) => {
        assert_eq!(occupied.insert(json!(13)), 12);
        assert_eq!(occupied.get(), 13);
    }
    Entry::Vacant(_) => unimplemented!(),
}

pub fn remove(self) -> Value

Takes the value of the entry out of the map, and returns it.

If serde_json’s “preserve_order” is enabled, .remove() is equivalent to [.swap_remove()][Self::swap_remove], replacing this entry’s position with the last element. If you need to preserve the relative order of the keys in the map, use [.shift_remove()][Self::shift_remove] instead.

Examples

use serde_json::map::Entry;

let mut map = serde_json::Map::new();
map.insert("serde".to_owned(), json!(12));

match map.entry("serde") {
    Entry::Occupied(occupied) => {
        assert_eq!(occupied.remove(), 12);
    }
    Entry::Vacant(_) => unimplemented!(),
}

pub fn remove_entry(self) -> (String, Value)

Removes the entry from the map, returning the stored key and value.

If serde_json’s “preserve_order” is enabled, .remove_entry() is equivalent to [.swap_remove_entry()][Self::swap_remove_entry], replacing this entry’s position with the last element. If you need to preserve the relative order of the keys in the map, use [.shift_remove_entry()][Self::shift_remove_entry] instead.

Examples

use serde_json::map::Entry;

let mut map = serde_json::Map::new();
map.insert("serde".to_owned(), json!(12));

match map.entry("serde") {
    Entry::Occupied(occupied) => {
        let (key, value) = occupied.remove_entry();
        assert_eq!(key, "serde");
        assert_eq!(value, 12);
    }
    Entry::Vacant(_) => unimplemented!(),
}