| commit | 4374190eae290bd39e1e104d6bffc463c56fd734 | [log] [tgz] |
|---|---|---|
| author | David LeGare <legare@google.com> | Mon Mar 14 23:38:43 2022 +0000 |
| committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | Mon Mar 14 23:38:43 2022 +0000 |
| tree | 07eb299a12f6f2438012ce9047c89b2b095f915d | |
| parent | b7c8957ce5152d9897634b74b5d911440cf40e23 [diff] | |
| parent | df849691f3074c6e5086ef022f2e6c808ff00407 [diff] |
Update TEST_MAPPING am: 22622b038b am: 3fa5691ab3 am: 70ced107a6 am: df849691f3 Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/memoffset/+/2006332 Change-Id: I334a3166153d339c28732c3a6cb5f0d2069edadd
C-Like offset_of functionality for Rust structs.
Introduces the following macros:
offset_of! for obtaining the offset of a member of a struct.offset_of_tuple! for obtaining the offset of a member of a tuple. (Requires Rust 1.20+)span_of! for obtaining the range that a field, or fields, span.memoffset works under no_std environments.
Add the following dependency to your Cargo.toml:
[dependencies] memoffset = "0.6"
These versions will compile fine with rustc versions greater or equal to 1.19.
use memoffset::{offset_of, span_of}; #[repr(C, packed)] struct Foo { a: u32, b: u32, c: [u8; 5], d: u32, } fn main() { assert_eq!(offset_of!(Foo, b), 4); assert_eq!(offset_of!(Foo, d), 4+4+5); assert_eq!(span_of!(Foo, a), 0..4); assert_eq!(span_of!(Foo, a .. c), 0..8); assert_eq!(span_of!(Foo, a ..= c), 0..13); assert_eq!(span_of!(Foo, ..= d), 0..17); assert_eq!(span_of!(Foo, b ..), 4..17); }
memoffset has experimental support for compile-time offset_of! on a nightly compiler.
In order to use it, you must enable the unstable_const crate feature and several compiler features.
Cargo.toml:
[dependencies.memoffset] version = "0.6" features = ["unstable_const"]
Your crate root: (lib.rs/main.rs)
#![feature(const_ptr_offset_from, const_refs_to_cell)]