Crate serde_piecewise_default

Uses serde’s Option<T> handling to let you easily specify defaults for all fields at once by implementing Default.

Panics

Will panic at compile time if you use #[derive(DeserializePiecewiseDefault)] on a struct with unnamed fields, a struct that does not implement Default, or an enum.

Examples

use serde::Deserialize;
use serde_piecewise_default::DeserializePiecewiseDefault;

#[derive(DeserializePiecewiseDefault, PartialEq, Eq, Debug)]
struct Example {
    value: u8,
    enabled: bool,
}

impl Default for Example {
    fn default() -> Self {
        Example {
            value: 20,
            enabled: true,
        }
    }
}

let data: Example = serde_json::from_str(r#"{"value": 8}"#).unwrap();
assert_eq!(data, Example { value: 8, enabled: true });
let data: Example = serde_json::from_str(r#"{"enabled": false}"#).unwrap();
assert_eq!(data, Example { value: 20, enabled: false });
let data: Example = serde_json::from_str("{}").unwrap();
assert_eq!(data, Example { value: 20, enabled: true });

Derive Macros

DeserializePiecewiseDefault

See the parent crate documentation for a high-level overview.