Struct serde_with::DisplayFromStr
source · pub struct DisplayFromStr;
Expand description
De/Serialize using Display
and FromStr
implementation
This allows deserializing a string as a number. It can be very useful for serialization formats like JSON, which do not support integer numbers and have to resort to strings to represent them.
Another use case is types with Display
and FromStr
implementations, but without serde
support, which can be found in some crates.
If you control the type you want to de/serialize, you can instead use the two derive macros, SerializeDisplay
and DeserializeFromStr
.
They properly implement the traits serde::Serialize
and serde::Deserialize
such that user of the type no longer have to use the serde_as
system.
Examples
#[serde_as]
#[derive(Deserialize, Serialize)]
struct A {
#[serde_as(as = "DisplayFromStr")]
mime: mime::Mime,
#[serde_as(as = "DisplayFromStr")]
number: u32,
}
let v: A = serde_json::from_value(json!({
"mime": "text/plain",
"number": "159",
})).unwrap();
assert_eq!(mime::TEXT_PLAIN, v.mime);
assert_eq!(159, v.number);
let x = A {
mime: mime::STAR_STAR,
number: 777,
};
assert_eq!(json!({ "mime": "*/*", "number": "777" }), serde_json::to_value(&x).unwrap());
Trait Implementations§
source§impl<'de, T> DeserializeAs<'de, T> for DisplayFromStrwhere
T: FromStr,
T::Err: Display,
impl<'de, T> DeserializeAs<'de, T> for DisplayFromStrwhere T: FromStr, T::Err: Display,
source§fn deserialize_as<D>(deserializer: D) -> Result<T, D::Error>where
D: Deserializer<'de>,
fn deserialize_as<D>(deserializer: D) -> Result<T, D::Error>where D: Deserializer<'de>,
Deserialize this value from the given Serde deserializer.
source§impl<T> SerializeAs<T> for DisplayFromStrwhere
T: Display,
impl<T> SerializeAs<T> for DisplayFromStrwhere T: Display,
source§fn serialize_as<S>(source: &T, serializer: S) -> Result<S::Ok, S::Error>where
S: Serializer,
fn serialize_as<S>(source: &T, serializer: S) -> Result<S::Ok, S::Error>where S: Serializer,
Serialize this value into the given Serde serializer.