pathmod_derive crate

Purpose

• Proc-macro crate providing #[derive(Accessor)] for structs (named and tuple).
• Generates inherent pub const accessor methods for each field:
  • Named fields: acc_<field>() -> pathmod::Accessor<Self, FieldTy>
  • Tuple fields: acc_<idx>() -> pathmod::Accessor<Self, FieldTy>

Behavior

• Accessors are built using core::mem::offset_of!, enabling const construction.
• Composition is available via the runtime type (Accessor) from the core crate.
• Unit structs and non-struct targets are rejected with clear compile errors.

How to use

• Most users should depend on pathmod and use pathmod::prelude::*; which re-exports this derive.
• If depending directly, add to Cargo.toml and import the macro: use pathmod_derive::Accessor; then annotate your types.

Example See top-level README for end-to-end examples. Minimal snippet:

use pathmod::prelude::*;

#[derive(Accessor)]
struct Address { city: String }

fn example() {
    let _acc = Address::acc_city();
}

Limitations and diagnostics

• Unit structs are not supported.
• Enums are not supported (future roadmap may add separate enum accessor derive).
• Visibility follows Rust rules: even though generated methods are pub, private types/field types aren’t accessible from outside their module.
• UI tests with trybuild cover error messages and generics visibility cases.

MSRV

• Intended MSRV 1.89+ (for core::mem::offset_of!).

License Dual-licensed under MIT or Apache-2.0.