Function find_key 

pub fn find_key<K, V>(object: &HashMap<K, V>, value: V) -> Option<&K>
where
    K: Eq + Hash,
    V: PartialEq,

Find the key in a map that corresponds to a given value. If no key corresponds to the value, return None.

Arguments

• object - A map of key-value pairs.
• value - The value to search for.

Returns

• Option<K> - The key that corresponds to the value, or None if no key corresponds to the value.

Examples

use lowdash::find_key;
let mut map = std::collections::HashMap::new();
map.insert("a", 1);
map.insert("b", 2);
map.insert("c", 3);
let result = find_key(&map, 2);
assert_eq!(result, Some(&"b"));

use lowdash::find_key;
let mut map = std::collections::HashMap::new();
map.insert("a", 1);
map.insert("b", 2);
map.insert("c", 3);
let result = find_key(&map, 4);
assert_eq!(result, None);

use lowdash::find_key;

#[derive(Debug, PartialEq, Eq, Hash)]
struct Person {
   name: String,
   age: u32,
}

let mut map = std::collections::HashMap::new();
map.insert(Person { name: "Alice".to_string(), age: 25 }, "Engineer");
map.insert(Person { name: "Bob".to_string(), age: 30 }, "Manager");
map.insert(Person { name: "Carol".to_string(), age: 35 }, "Director");

let result = find_key(&map, "Manager");
assert_eq!(result, Some(&Person { name: "Bob".to_string(), age: 30 }));