assert-offset
| Crates.io | assert-offset |
| lib.rs | assert-offset |
| version | |
| source | src |
| created_at | 2025-01-14 21:29:10.468751+00 |
| updated_at | 2025-01-14 21:40:35.733827+00 |
| description | Derive macro for asserting the memory offset of fields in a struct. |
| homepage | |
| repository | https://github.com/cohaereo/assert-offset |
| max_upload_size | |
| id | 1516704 |
| Cargo.toml error: | TOML parse error at line 17, column 1 | 17 | autolib = false | ^^^^^^^ unknown field `autolib`, expected one of `name`, `version`, `edition`, `authors`, `description`, `readme`, `license`, `repository`, `homepage`, `documentation`, `build`, `resolver`, `links`, `default-run`, `default_dash_run`, `rust-version`, `rust_dash_version`, `rust_version`, `license-file`, `license_dash_file`, `license_file`, `licenseFile`, `license_capital_file`, `forced-target`, `forced_dash_target`, `autobins`, `autotests`, `autoexamples`, `autobenches`, `publish`, `metadata`, `keywords`, `categories`, `exclude`, `include` |
| size | 0 |
cohae (cohaereo)
documentation
README
assert-offset
assert-offset is a simple Rust derive macro for asserting memory offsets within structures.
This can be useful for low level FFI and/or embedded development.
⚠ This crate does not change field offsets, it merely asserts that they are at the expected offsets.
Examples
Usage
use assert_offset::AssertOffsets;
#[derive(AssertOffsets)]
#[repr(C)]
pub struct Foo {
// Try reordering these fields or changing their types
pub a: u8,
#[offset(0x2)]
pub b: u16,
}
Failing Example
use assert_offset::AssertOffsets;
// Note that we're not using #[repr(C)] here
#[derive(AssertOffsets)]
pub struct Foo {
pub a: u8,
// Rust (usually) puts this field at the start of the struct,
// because u16 has a higher alignment requirement than u8
#[offset(0x2)] // Changing this offset to 0x0 (should) fix the error
pub b: u16,
}
Compiler Error
error[E0080]: evaluation of constant value failed
--> src\main.rs:3:10
|
3 | #[derive(AssertOffsets)]
| ^^^^^^^^^^^^^ the evaluated program panicked at 'Field `Foo::b` is not at expected offset 0x2'
License
This project is licensed under the MIT License.