| commit | 33b450ea942b38ee30d6f51108d4280134e63fcd | [log] [tgz] |
|---|---|---|
| author | Treehugger Robot <[email protected]> | Wed Jun 15 21:01:02 2022 +0000 |
| committer | Automerger Merge Worker <[email protected]> | Wed Jun 15 21:01:02 2022 +0000 |
| tree | ada5981c5c47b3e6bbd21aa169876f5ded310f0b | |
| parent | 5a689639a7798f1171fc22011a75b51ab2eb0de0 [diff] | |
| parent | 1eb3829c7773ba00799b5a4ea7723bffc7794862 [diff] |
Merge "Update TEST_MAPPING" am: 90380428c5 am: 1eb3829c77 Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/memoffset/+/2125993 Change-Id: I4d4c6d790a405eff7067f0aa2105973fb09b7174 Signed-off-by: Automerger Merge Worker <[email protected]>
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)]