# facet-default
[](https://crates.io/crates/facet-default)
[](https://docs.rs/facet-default)
[](https://github.com/facet-rs/facet/blob/main/LICENSE-MIT)
`facet-default` derives [`Default`](https://doc.rust-lang.org/std/default/trait.Default.html)
for your types through facet's plugin system, letting you supply per-field
defaults directly in the struct definition rather than writing a manual `impl`.
```rust
use facet::Facet;
use facet_default as default;
#[derive(Facet, Debug)]
#[facet(derive(Default))]
pub struct Config {
#[facet(default::value = "localhost")]
host: String,
#[facet(default::value = 8080u16)]
port: u16,
#[facet(default::func = "default_timeout")]
timeout: std::time::Duration,
// No attribute = uses Default::default()
debug: bool,
}
fn default_timeout() -> std::time::Duration {
std::time::Duration::from_secs(30)
}
```
## Attributes
### Field level
- `#[facet(default::value = literal)]` — use a literal value (converted via `.into()`)
- `#[facet(default::func = "path")]` — call a function to get the default value
Fields without attributes fall back to `Default::default()`. For numeric literals,
include a type suffix (e.g. `8080u16`) to avoid ambiguity. String literals are
automatically converted via `.into()`.
## Enums
For enums, mark the default variant with `#[facet(default::variant)]`:
```rust
use facet::Facet;
use facet_default as default;
#[derive(Facet, Debug, PartialEq)]
#[facet(derive(Default))]
#[repr(u8)]
pub enum Status {
#[facet(default::variant)]
Pending,
Active,
Done,
}
assert_eq!(Status::default(), Status::Pending);
```
Enum variants with fields work the same way — each field uses its own default attributes.
## Sponsors
Thanks to all individual sponsors:
<p> <a href="https://github.com/sponsors/fasterthanlime">
<picture>
<source media="(prefers-color-scheme: dark)" srcset="https://github.com/facet-rs/facet/raw/main/static/sponsors-v3/github-dark.svg">
<img src="https://github.com/facet-rs/facet/raw/main/static/sponsors-v3/github-light.svg" height="40" alt="GitHub Sponsors">
</picture>
</a> <a href="https://patreon.com/fasterthanlime">
<picture>
<source media="(prefers-color-scheme: dark)" srcset="https://github.com/facet-rs/facet/raw/main/static/sponsors-v3/patreon-dark.svg">
<img src="https://github.com/facet-rs/facet/raw/main/static/sponsors-v3/patreon-light.svg" height="40" alt="Patreon">
</picture>
</a> </p>
...along with corporate sponsors:
<p> <a href="https://aws.amazon.com">
<picture>
<source media="(prefers-color-scheme: dark)" srcset="https://github.com/facet-rs/facet/raw/main/static/sponsors-v3/aws-dark.svg">
<img src="https://github.com/facet-rs/facet/raw/main/static/sponsors-v3/aws-light.svg" height="40" alt="AWS">
</picture>
</a> <a href="https://zed.dev">
<picture>
<source media="(prefers-color-scheme: dark)" srcset="https://github.com/facet-rs/facet/raw/main/static/sponsors-v3/zed-dark.svg">
<img src="https://github.com/facet-rs/facet/raw/main/static/sponsors-v3/zed-light.svg" height="40" alt="Zed">
</picture>
</a> <a href="https://depot.dev?utm_source=facet">
<picture>
<source media="(prefers-color-scheme: dark)" srcset="https://github.com/facet-rs/facet/raw/main/static/sponsors-v3/depot-dark.svg">
<img src="https://github.com/facet-rs/facet/raw/main/static/sponsors-v3/depot-light.svg" height="40" alt="Depot">
</picture>
</a> </p>
...without whom this work could not exist.
## Special thanks
The facet logo was drawn by [Misiasart](https://misiasart.com/).
## License
Licensed under either of:
- Apache License, Version 2.0 ([LICENSE-APACHE](https://github.com/facet-rs/facet/blob/main/LICENSE-APACHE) or <http://www.apache.org/licenses/LICENSE-2.0>)
- MIT license ([LICENSE-MIT](https://github.com/facet-rs/facet/blob/main/LICENSE-MIT) or <http://opensource.org/licenses/MIT>)
at your option.