snow/
utils.rs

1use std::ops::{Deref, DerefMut};
2
3/// Toggle is similar to Option, except that even in the Off/"None" case, there is still
4/// an owned allocated inner object. This is useful for holding onto pre-allocated objects
5/// that can be toggled as enabled.
6pub struct Toggle<T> {
7    inner: T,
8    on:    bool,
9}
10
11impl<T> Toggle<T> {
12    pub fn on(inner: T) -> Self {
13        Self { inner, on: true }
14    }
15
16    pub fn off(inner: T) -> Self {
17        Self { inner, on: false }
18    }
19
20    pub fn enable(&mut self) {
21        self.on = true;
22    }
23
24    pub fn is_on(&self) -> bool {
25        self.on
26    }
27
28    pub fn get(&self) -> Option<&T> {
29        if self.on {
30            Some(&self.inner)
31        } else {
32            None
33        }
34    }
35}
36
37impl<T> Deref for Toggle<T> {
38    type Target = T;
39
40    fn deref(&self) -> &T {
41        &self.inner
42    }
43}
44
45impl<T> DerefMut for Toggle<T> {
46    fn deref_mut(&mut self) -> &mut T {
47        &mut self.inner
48    }
49}
snow/utils.rs

snow/
utils.rs
