bevy/crates/bevy_state
Christian Hughes b4071ca370
Add World::get_resource_or_init as an alternative to World::get_resource_or_insert_with (#15758)
# Objective

If a `Resource` implements `FromWorld` or `Default`, it's nicer to be
able to write:

```rust
let foo = world.get_resource_or_init::<Foo>();
```

Rather than:

```rust
let foo = world.get_resource_or_insert_with(Foo::default);
```

The latter is also not possible if a type implements `FromWorld` only,
and not `Default`.

## Solution

Added:

```rust
impl World {
    pub fn get_resource_or_init<R: Resource + FromWorld>(&mut self) -> Mut<'_, R>;
}
```

Turns out all current in-engine uses of `get_resource_or_insert_with`
are exactly the above, so they've also been replaced.

## Testing

- Added a doc-test.
- Also added a doc-test for `World::get_resource_or_insert_with`.
2024-10-09 20:56:26 +00:00
..
macros Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
src Add World::get_resource_or_init as an alternative to World::get_resource_or_insert_with (#15758) 2024-10-09 20:56:26 +00:00
Cargo.toml Remove manual --cfg docsrs (#14376) 2024-07-22 18:58:04 +00:00