| commit | 19b3b2f8f751852029d336b435519fbad4293ec5 | [log] [tgz] |
|---|---|---|
| author | Matthew Maurer <[email protected]> | Tue May 31 19:06:24 2022 +0000 |
| committer | Automerger Merge Worker <[email protected]> | Tue May 31 19:06:24 2022 +0000 |
| tree | 797db5196ce61921f597653bef3c6aecd472dd88 | |
| parent | ac2bc58bd3c1d9e205f2d39d1ff243d779b5d177 [diff] | |
| parent | d6c0f3b5f802dcc59a5f4b830a2c9a78e81008df [diff] |
Update TEST_MAPPING am: 7b7af6725c am: ba217ddbae am: 5a689639a7 am: c9151b63c7 am: d6c0f3b5f8 Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/memoffset/+/2107071 Change-Id: Ibcd4eb61e68eeb08b6a16cb92afc4db3a4c99f5d 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)]