#offset #mem #offset_of #offsetof

no-std memoffset

offset_of functionality for Rust structs

3 unstable releases

0.2.1 Jan 15, 2018
0.2.0 Jan 13, 2018
0.1.0 Oct 17, 2017

#4 in No standard library

Download history 44870/week @ 2018-10-04 44380/week @ 2018-10-11 40493/week @ 2018-10-18 48869/week @ 2018-10-25 46702/week @ 2018-11-01 47413/week @ 2018-11-08 47050/week @ 2018-11-15 42352/week @ 2018-11-22 49267/week @ 2018-11-29 54582/week @ 2018-12-06 53575/week @ 2018-12-13 38200/week @ 2018-12-20 15323/week @ 2018-12-27 52878/week @ 2019-01-03 53094/week @ 2019-01-10

82,186 downloads per month
Used in 1,285 crates (3 directly)

MIT license

17KB
229 lines

memoffset

C-Like offset_of functionality for Rust structs.

Introduces the following macros:

  • offset_of! for obtaining the offset of a member of a struct.
  • span_of! for obtaining the range that a field, or fields, span.

memoffset works under no_std environments.

Usage

Add the following dependency to your Cargo.toml:

[dependencies]
memoffset = "0.2"

Add the following lines at the top of your main.rs or lib.rs files.

#[macro_use]
extern crate memoffset;

Examples

#[repr(C, packed)]
struct Foo {
	a: u32,
	b: u32,
	c: [u8; 5],
	d: u32,
}

assert_eq!(offset_of!(Foo, b), 4);
assert_eq!(offset_of!(Foo, c[3]), 11);

assert_eq!(span_of!(Foo, a),          0..4);
assert_eq!(span_of!(Foo, a ..  c),    0..8);
assert_eq!(span_of!(Foo, a ..  c[1]), 0..9);
assert_eq!(span_of!(Foo, a ..= c[1]), 0..10);
assert_eq!(span_of!(Foo, ..= d),      0..14);
assert_eq!(span_of!(Foo, b ..),       4..17);

No runtime deps