Macro rumtk_cache_get 

macro_rules! rumtk_cache_get {
    ( $cache:expr, $key:expr, $default_function:expr ) => { ... };
}

Retrieves the cached item in immutable mode.

use rumtk_core::{rumtk_cache_fetch, rumtk_cache_push, rumtk_cache_get};
use rumtk_core::cache::{new_cache, LazyRUMCache, cache_push, cache_get};
use std::sync::Arc;

type StringCache = LazyRUMCache<String, Vec<String>>;

fn init_cache(k: &String) -> Vec<String> {
   vec![]
}

let mut cache: StringCache = new_cache();
static DEFAULT_VEC: Vec<String> = vec![];

let test_key: String = String::from("Hello World");
let test_value: String = String::from("?????");

rumtk_cache_fetch!(
    &raw mut cache,
    &test_key,
    init_cache
);

rumtk_cache_push!(
    &raw mut cache,
    &test_key,
    &vec![test_value.clone()]
);

let v = rumtk_cache_get!(
    &raw mut cache,
    &test_key,
    &DEFAULT_VEC
);

assert_eq!(test_value.as_str(), v.get(0).unwrap().as_str(), "The inserted key is not the same to what was passed as input!");