RefCast
Safely cast &T
to &U
where the struct U
contains a single field of
type T
.
[]
= "0.2"
Basic example
extern crate ref_cast;
use RefCast;
;
Realistic example
Suppose we have a multidimensional array represented in a flat buffer in row-major order for performance reasons, but we want to expose an indexing operation that works in column-major order because it is more intuitive in the context of our application.
const MAP_WIDTH: usize = 4;
;
// `tilemap[x][y]` should give us `tilemap.storage[y * MAP_WIDTH + x]`.
The signature of the Index
trait in Rust is such that the output is
forced to be borrowed from the type being indexed. So something like the
following is not going to work.
// Does not work! The output of Index must be a reference that is
// borrowed from self. Here the type Column is not a reference.
Here is a working approach using RefCast
.
;
// Implement `tilemap[x][y]` as `tilemap[x..][y * MAP_WIDTH]`.
License
Licensed under either of
- Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.