Field Path

Field Path provides a lightweight and type-safe abstraction for referencing and accessing nested fields within structs.

The crate is designed to make it easier to generically inspect or mutate fields without relying on heavy reflection systems or unsafe code. It does this through a combination of field identifiers and accessors that preserve type information.

Core Concepts

• Field: Represents a unique, type-safe identifier for a field path within a struct.

• Accessor: A generic wrapper providing read and write access to a field.

• FieldAccessorRegistry: A mapping between fields and their accessors for lookup and dynamic use.

  (only available with the "registry" feature, enabled by default)

Together, these components allow building flexible systems that can access or manipulate struct data without tightly coupling to specific types.

Example

use field_path::registry::FieldAccessorRegistry;
use field_path::field;
use field_path::accessor;

#[derive(Default)]
struct Vec2<T> {
    pub x: T,
    pub y: T,
}

let mut registry = FieldAccessorRegistry::default();
let field = field!(<Vec2<f32>>::x);

// Register accessors.
registry.register_typed(field, accessor!(<Vec2<f32>>::x));

// Access field generically.
let mut v = Vec2::default();
let accessor =
    registry.get::<Vec2<f32>, f32>(&field.untyped()).unwrap();

*accessor.get_mut(&mut v) = 42.0;
assert_eq!(accessor.get_ref(&v), &42.0);

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License

field_path is dual-licensed under either:

• MIT License (LICENSE-MIT or http://opensource.org/licenses/MIT)
• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)

This means you can select the license you prefer! This dual-licensing approach is the de-facto standard in the Rust ecosystem and there are very good reasons to include both.