# Objective
This PR introduces an `AsyncSeekForwardExt` trait, which I forgot in my
previous PR #14194.
This new trait is analogous to `AsyncSeekExt` and allows all
implementors of `AsyncSeekForward` to directly use the `seek_forward`
function in async contexts.
## Solution
- Implement a new `AsyncSeekForwardExt` trait
- Automatically implement this trait for all types that implement
`AsyncSeekForward`
## Showcase
This new trait allows a similar API to the previous Bevy version:
```rust
#[derive(Default)]
struct UniverseLoader;
#[derive(Asset, TypePath, Debug)]
struct JustALilAsteroid([u8; 128]);
impl AssetLoader for UniverseLoader {
type Asset = JustALilAsteroid;
type Settings = ();
type Error = std::io::Error;
async fn load<'a>(
&'a self,
reader: &'a mut Reader<'a>,
_settings: &'a Self::Settings,
_context: &'a mut LoadContext<'_>,
) -> Result<Self::Asset, Self::Error> {
// read the asteroids entry table
let entry_offset: u64 = /* ... */;
let current_offset: u64 = reader.seek_forward(0).await?;
// jump to the entry
reader.seek_forward(entry_offset - current_offset).await?;
let mut asteroid_buf = [0; 128];
reader.read_exact(&mut asteroid_buf).await?;
Ok(JustALilAsteroid(asteroid_buf))
}
fn extensions(&self) -> &[&str] {
&["celestial"]
}
}
```
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