Struct DisplayFromStr 

pub struct DisplayFromStr;

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

impl<'de, T> DeserializeAs<'de, T> for DisplayFromStr

where T: FromStr, T::Err: Display,

fn deserialize_as<D>(deserializer: D) -> Result<T, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<T> SerializeAs<T> for DisplayFromStr

where T: Display,

fn serialize_as<S>(source: &T, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 0 bytes