repr_offset allows computing and safely using field offsets from types with a defined layout.

Currently only #[repr(C)]/#[repr(C,packed)]/#[repr(C,align)] structs are supported.

Features

These are some of the features this library provides:

• The ReprOffset derive macro, which outputs associated constants with the offsets of fields, and implements the GetFieldOffset trait for each field.

• The FieldOffset type (how offsets are represented), with methods for operating on a field through a pointer to the struct, including getting a reference(or pointer) to the field.

• The unsafe_struct_field_offsets macro as an alternative to the ReprOffset derive macro, most useful when the "derive" feature is disabled.

• The GetFieldOffset trait, for getting the FieldOffset for a field, and the OFF!, off, PUB_OFF!, and pub_off macros for getting the FieldOffset for a field with a convenient syntax.

• The extension traits from the ext module, which define methods for operating on a field, given a FieldOffset.

Examples

For examples you can look at the examples section of the documentation for the root module of the repr_offset crate

Future plans

None for now.

Cargo features

These are the cargo features in repr_offset:

• derive (disabled by default): Enables the ReprOffset derive macro. This requires the same Rust versions as syn, which is currently >= 1.56.0.

• "for_examples" (disabled by default): Enables the for_examples module, with types used in documentation examples.

Adding the "derive" feature to the Cargo.toml file:

repr_offset = { version = "0.2", features = ["derive"] }

no-std support

This library is unconditionally #![no_std],and that is unlikely to change in the future.

Minimum Rust version

This crate support Rust back to 1.41.0.

License

Licensed under the Zlib license