Struct Derived 

pub struct Derived;

The adapter that uses the derived implementation of a type.

Adapters on a type (see container adapters) replace its derived implementation. Adapters which wrap another adapter can wrap the derived implementation with Derived, which is written as _ in the attribute. This is how values are checked or converted after the derived implementation deserialized them:

use deser::{Deserialize, State};
use deser::de::SinkHandle;

/// Deserializes with `A`, missing values are the default.
pub struct DefaultIfMissing<A>(std::marker::PhantomData<A>);

impl<'de, T: Default + Send, A: Deserialize<'de, T>> Deserialize<'de, T>
    for DefaultIfMissing<A>
{
    fn deserialize_into<'out>(
        out: &'out mut Option<T>,
        state: &mut State,
    ) -> SinkHandle<'out, 'de> {
        A::deserialize_into(out, state)
    }

    fn initial_value() -> Option<T> {
        Some(T::default())
    }
}

#[derive(Deserialize, Default)]
#[deser(deserialize_as = DefaultIfMissing<_>)]
struct Limits {
    max_connections: u32,
}

#[derive(Deserialize)]
struct Config {
    limits: Limits,
}

// the limits are missing
let config: Config = deser_json::from_str("{}").unwrap();
assert_eq!(config.limits.max_connections, 0);

The derived implementation is only available through this adapter for the directions that have an adapter with _.

Trait Implementations

impl<'de, T: DerivedDeserialize<'de>> Deserialize<'de, T> for Derived

fn deserialize_into<'out>( out: &'out mut Option<T>, state: &mut State, ) -> SinkHandle<'out, 'de>

Creates a sink that deserializes the value into the given slot.

fn expecting() -> Cow<'static, str>

Returns what the value expects, for error messages.

fn describe_type(d: &mut dyn Describe)

Describes the Rust shape of the type.

fn initial_value() -> Option<T>

Provides the value of a missing struct field.

fn deserialize_update<'out>( value: &'out mut T, state: &mut State, ) -> SinkHandle<'out, 'de>

Creates a sink that updates an existing value.

fn deserialize_atom( slot: &mut Slot<T, Self>, atom: Atom<'_>, state: &mut State, ) -> Result<(), Error>

Deserializes an atom into the slot.

fn deserialize_borrowed_atom( slot: &mut Slot<T, Self>, atom: Atom<'de>, state: &mut State, ) -> Result<(), Error>

Deserializes an atom that borrows from the data being deserialized into the slot.

impl<T: DerivedSerialize + ?Sized> Serialize<T> for Derived

fn serialize<'a>(value: &'a T, state: &mut State) -> Result<Emit<'a>, Error>

Serializes the value.

fn finish(value: &T, state: &mut State) -> Result<(), Error>

Invoked after the serialization finished.

fn is_optional(value: &T) -> bool

Checks if the value represents an optional value.

fn container_shape(value: &T) -> ContainerShape

Returns the shape of the value if it’s a map or sequence.

fn describe(value: &T, d: &mut dyn Describe)

Describes the Rust shape of the value.