&U where the struct
U contains a single field of
 = "1.0"
use RefCast; ;
#[repr(transparent)] is required in order for the conversion to be
sound. The derive macro will refuse to compile if that is not present.
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
; // Implement `tilemap[x][y]` as `tilemap[x..][y * MAP_WIDTH]`.