2 releases
0.1.1 | May 18, 2022 |
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0.1.0 | Apr 27, 2022 |
#289 in No standard library
11KB
174 lines
cell-ref
This crate provides a Cell
type (like the standard library’s
Cell
) with methods for safely mutating and inspecting the
inner value by reference (with
and with_mut
).
For Copy
types, this is implemented with get
and
set
, but through an extension trait, this crate
provides those same operations for types that are Default
but not
Copy
. A get
method is also available for types that are both
Default
and Clone
.
This crate depends only on core
, so it can be used inside no_std
environments.
Example
use cell_ref::{Cell, CellExt};
let c1 = Cell::new(2_u8);
c1.with_mut(|x| *x += 3);
assert!(c1.get() == 5);
let c2 = Cell::new(vec![1, 2, 3]);
c2.with_mut(|v| v.push(4)); // Works even though `Vec` isn't `Copy`
assert_eq!(c2.with(Vec::len), 4);
let v = c2.get(); // Clones the vector