Crate getters_by_type

This crate provides GettersByType derive macro for structs, which implements a getter method for each type they contain.

The generated methods start with the prefix get_fields_ and end with a transcription of the type they refer.

Example using GettersByType :

use getters_by_type::GettersByType;
#[derive(GettersByType)]
struct Foo {
    first: i32,
    second: i32,
    third: i32,
}

let object = Foo { first: 6, second: 12, third: 24 };

// Let's sum all the i32 fields with a fold expression:
assert_eq!(object.get_fields_i32().iter().fold(0, |acc, x| **x + acc), 42);

As you notice, the getter methods return an array containing references to all the fields of the same type. In that example, the return type of the method get_fields_i32 would be [&i32; 3].

This crate also provides a mut version GettersMutByType which also adds a mut version for those methods.

In this case, the generated methods start with the prefix get_mut_fields_ instead.

Example using GettersMutByType :

use getters_by_type::GettersMutByType;

#[derive(Default)]
struct Updater {}
impl Updater {
    fn update(&mut self) {/*...*/}
}

#[derive(GettersMutByType, Default)]
struct Foo {
    first: Updater,
    second: Updater,
    /*...*/
    onehundredth: Updater,
}

let mut object = Foo::default();

// Let's update all the Updater fields
for updater in object.get_mut_fields_updater().iter_mut() {
    updater.update();
}

In this example, the return type of the method get_mut_fields_updater would be [&mut Updater; 3]. There is no dynamic memory allocation happening within the getter methods, as they just return a fixed array with references. There isn’t also unsafe code being generated. For more documentation and examples, see each respective documentation section.

Derive Macros

• GettersByType
  The GettersByType macro automatically generates an impl for the given struct, implementing a getter method for each different type contained within the struct.
• GettersMutByType
  The GettersMutByType macro automatically generates an impl for the given struct, implementing a getter method for each different type contained within the struct.