Wrapper Types

Rust has a variety of “wrapper” types, such as RefCell and Mutex, that provide special behavior for values. Accessing these values can take a non-trivial amount of time. If multiple such values are typically accessed together, it may be better to put them within a single wrapper.

For example, a struct like this:


#![allow(unused)]
fn main() {
use std::sync::{Arc, Mutex};
struct S {
    x: Arc<Mutex<u32>>,
    y: Arc<Mutex<u32>>,
}
}

may be better represented like this:


#![allow(unused)]
fn main() {
use std::sync::{Arc, Mutex};
struct S {
    xy: Arc<Mutex<(u32, u32)>>,
}
}

Whether or not this helps performance will depend on the exact access patterns of the values. Example.