Derive Macro bevy_derive::Deref
source · #[derive(Deref)]
{
// Attributes available to this derive:
#[deref]
}
Expand description
Implements Deref
for structs. This is especially useful when utilizing the newtype pattern.
For single-field structs, the implementation automatically uses that field.
For multi-field structs, you must specify which field to use with the #[deref]
attribute.
If you need DerefMut
as well, consider using the other derive macro alongside
this one.
§Example
§Tuple Structs
Using a single-field struct:
use bevy_derive::Deref;
#[derive(Deref)]
struct MyNewtype(String);
let foo = MyNewtype(String::from("Hello"));
assert_eq!("Hello", *foo);
Using a multi-field struct:
use bevy_derive::Deref;
#[derive(Deref)]
struct MyStruct<T>(#[deref] String, PhantomData<T>);
let foo = MyStruct(String::from("Hello"), PhantomData::<usize>);
assert_eq!("Hello", *foo);
§Named Structs
Using a single-field struct:
use bevy_derive::{Deref, DerefMut};
#[derive(Deref, DerefMut)]
struct MyStruct {
value: String,
}
let foo = MyStruct {
value: String::from("Hello")
};
assert_eq!("Hello", *foo);
Using a multi-field struct:
use bevy_derive::{Deref, DerefMut};
#[derive(Deref, DerefMut)]
struct MyStruct<T> {
#[deref]
value: String,
_phantom: PhantomData<T>,
}
let foo = MyStruct {
value:String::from("Hello"),
_phantom:PhantomData::<usize>
};
assert_eq!("Hello", *foo);