#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

#3 in No standard library

Download history 31454/week @ 2018-09-11 39456/week @ 2018-09-18 37679/week @ 2018-09-25 41396/week @ 2018-10-02 45328/week @ 2018-10-09 43205/week @ 2018-10-16 40654/week @ 2018-10-23 48585/week @ 2018-10-30 47448/week @ 2018-11-06 46599/week @ 2018-11-13 47217/week @ 2018-11-20 43023/week @ 2018-11-27 42653/week @ 2018-12-04

82,186 downloads per month
Used in 2,092 crates (1 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