Crate struct_field_offsets

This crate provides a field_offsets member over struct declaration that adorns the FieldOffsets macro. For example, this can be used in FFI scenarios where asserting the offset of each field among the various languages struct becomes a concern.

use struct_field_offsets::FieldOffsets;

// at declaration site
#[derive(FieldOffsets)]
#[repr(C)]
struct Data {
    x: i32,
    y: i32,
    label: [u8;8]
}
 
// in the code
let offsets = Data::field_offsets();
for (name,offset) in offsets {
println!("field {name} offset is {offset}.");
}
// prints:
// > field x offset is 0.
// > field y offset is 4.
// > field label offset is 8.

In your Cargo.toml:

[dependencies]
struct-field-offsets = "*"

Derive Macros

FieldOffsets