A crate for mucking around with piles of bytes.
This crate lets you safely perform "bit cast" operations between data types. That's where you take a value and just reinterpret the bits as being some other type of value, without changing the bits.
as
keywordFrom
traitf32::to_bits
, just generalized to let you
convert between all sorts of data types.When a slice is involved it's not a direct bitcast. Instead, the cast_slice
and cast_slice_mut
functions will pull apart a slice's data and give you a new
slice that's the same span of memory just viewed as the new type. If the size of
the slice's element changes then the length of the slice you get back will be
changed accordingly.
This lets you cast a slice of color values into a slice of u8
and send it to
the GPU, or things like that. I'm sure there's other examples, but honestly this
crate is as popular as it is mostly because of Rust's 3D graphics community
wanting to cast slices of different types into byte slices for sending to the
GPU. Hi friends! Push those vertices, or whatever it is that you all do.
While bytemuck
is full of unsafe code, I've also started a "sibling crate"
called bitfrob, which is where
operations that are 100% safe will be added.
bytemuck
in bigger projects.bytemuck
crate will continue to work with rustc-1.34
for at least the rest of the 1.y.z
versions.Future Plans: Once the Safe Transmute Project completes and
stabilizes ("eventually") this crate will be updated to use that as the
underlying mechanism for transmutation bounds, and a 2.0 version of bytemuck
will be released. The hope is for the 1.0 to 2.0 transition to be as seamless as
possible, but the future is always uncertain.