Function serde_aux::field_attributes::deserialize_default_from_null [−][src]
pub fn deserialize_default_from_null<'de, D, T>(
deserializer: D
) -> Result<T, D::Error> where
D: Deserializer<'de>,
T: Deserialize<'de> + Default,
Deserializes default value from nullable value. If the original value is null
,
Default::default()
is used.
Example:
use serde_aux::prelude::*; #[derive(serde::Serialize, serde::Deserialize, Debug)] struct MyStruct { #[serde(deserialize_with = "deserialize_default_from_null")] null_as_default: u64, } let s = r#" { "null_as_default": 42 } "#; let a: MyStruct = serde_json::from_str(s).unwrap(); assert_eq!(a.null_as_default, 42); let s = r#" { "null_as_default": null } "#; let a: MyStruct = serde_json::from_str(s).unwrap(); assert_eq!(a.null_as_default, 0); let s = r#" { "null_as_default": "wrong_type" } "#; assert!(serde_json::from_str::<MyStruct>(s).is_err());