const-zero

Crates.ioconst-zero
lib.rsconst-zero
version0.1.1
sourcesrc
created_at2021-02-26 14:06:38.142199
updated_at2023-08-10 12:52:21.332979
descriptiona const mem::zeroed
homepage
repositoryhttps://github.com/maxbla/const-zero
max_upload_size
id360933
size17,801
Max Blachman (maxbla)

documentation

README

Const-zero

Provides a const version of core::mem::zeroed().

Example Usage

Example usage:

use const_zero::const_zero;
struct OpaqueStruct {
    nothing: core::ffi::c_void,
};
static mut zeroed_opaque: OpaqueStruct = unsafe {const_zero!(OpaqueStruct)};

Ideally const_zero would be a generic function, but const generics need more development first (const_fn_transmute, const_generics, const_evaluatable_checked)

Differences with std::mem::zeroed

const_zero zeroes padding bits, while std::mem::zeroed doesn't

How does it work?

The simplified version is

union TypeAsBytes<T> {
    bytes: [u8; core::mem::size_of::<T>()],
    inner: T,
};

which can be initalized with

TypeAsBytes {bytes: [0; core::mem::size_of::<T>()]};

Feel free to use this trick in your code if you want to skip out on a dependency

Commit count: 8

cargo fmt