Struct serde_with::TryFromIntoRef
source · pub struct TryFromIntoRef<T>(/* private fields */);
Expand description
Serialize a reference value by converting to/from a proxy type with serde support.
This adapter serializes a type O
by converting it into a second type T
and serializing T
.
Deserializing works analogue, by deserializing a T
and then converting into O
.
struct S {
#[serde_as(as = "TryFromIntoRef<T>")]
value: O,
}
For serialization O
needs to be for<'a> &'a O: TryInto<T>
.
For deserialization the opposite T: TryInto<O>
is required.
In both cases the TryInto::Error
type must implement Display
.
Note: FromIntoRef
is the more specialized version of this adapter which uses the infallible Into
trait instead.
TryFromIntoRef
is strictly more general and can also be used where FromIntoRef
is applicable.
The example shows a use case, when only the deserialization behavior is fallible, but not serializing.
§Example
#[derive(Debug, PartialEq)]
enum Boollike {
True,
False,
}
impl From<Boollike> for u8 { ... }
impl TryFrom<u8> for Boollike {
type Error = String;
fn try_from(v: u8) -> Result<Self, Self::Error> {
match v {
0 => Ok(Boollike::False),
1 => Ok(Boollike::True),
_ => Err(format!("Boolikes can only be constructed from 0 or 1 but found {}", v))
}
}
}
#[serde_as]
#[derive(Deserialize, Serialize)]
struct Data {
#[serde_as(as = "TryFromIntoRef<u8>")]
b: Boollike,
}
let data = Data {
b: Boollike::True,
};
// Define our expected JSON form
let j = json!({
"b": 1,
});
// Ensure serialization and deserialization produce the expected results
assert_eq!(j, serde_json::to_value(&data).unwrap());
assert_eq!(data, serde_json::from_value(j).unwrap());
// Numbers besides 0 or 1 should be an error
let j = json!({
"b": 2,
});
assert_eq!("Boolikes can only be constructed from 0 or 1 but found 2", serde_json::from_value::<Data>(j).unwrap_err().to_string());
Trait Implementations§
source§impl<'de, T, U> DeserializeAs<'de, T> for TryFromIntoRef<U>
impl<'de, T, U> DeserializeAs<'de, T> for TryFromIntoRef<U>
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, U: JsonSchema> JsonSchemaAs<T> for TryFromIntoRef<U>
Available on crate feature schemars_0_8
only.
impl<T, U: JsonSchema> JsonSchemaAs<T> for TryFromIntoRef<U>
Available on crate feature
schemars_0_8
only.source§fn schema_name() -> String
fn schema_name() -> String
The name of the generated JSON Schema. Read more
source§fn schema_id() -> Cow<'static, str>
fn schema_id() -> Cow<'static, str>
Returns a string that uniquely identifies the schema produced by this type. Read more
source§fn json_schema(gen: &mut SchemaGenerator) -> Schema
fn json_schema(gen: &mut SchemaGenerator) -> Schema
Generates a JSON Schema for this type. Read more
source§fn is_referenceable() -> bool
fn is_referenceable() -> bool
Whether JSON Schemas generated for this type should be re-used where possible using the
$ref
keyword. Read moresource§impl<T, U> SerializeAs<T> for TryFromIntoRef<U>
impl<T, U> SerializeAs<T> for TryFromIntoRef<U>
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.
Auto Trait Implementations§
impl<T> Freeze for TryFromIntoRef<T>
impl<T> RefUnwindSafe for TryFromIntoRef<T>where
T: RefUnwindSafe,
impl<T> Send for TryFromIntoRef<T>where
T: Send,
impl<T> Sync for TryFromIntoRef<T>where
T: Sync,
impl<T> Unpin for TryFromIntoRef<T>where
T: Unpin,
impl<T> UnwindSafe for TryFromIntoRef<T>where
T: UnwindSafe,
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more