Trait serde::de::SeqAccess

pub trait SeqAccess<'de> {
type Error: Error;
    fn next_element_seed<T>(
        &mut self, 
        seed: T
    ) -> Result<Option<T::Value>, Self::Error>
    where
        T: DeserializeSeed<'de>;

    fn next_element<T>(&mut self) -> Result<Option<T>, Self::Error>
    where
        T: Deserialize<'de>,
    { ... }
    fn size_hint(&self) -> Option<usize> { ... }
}

Provides a Visitor access to each element of a sequence in the input.

This is a trait that a Deserializer passes to a Visitor implementation, which deserializes each item in a sequence.

Lifetime

The 'de lifetime of this trait is the lifetime of data that may be borrowed by deserialized sequence elements. See the page Understanding deserializer lifetimes for a more detailed explanation of these lifetimes.

Example implementation

The example data format presented on the website demonstrates an implementation of SeqAccess for a basic JSON data format.

Associated Types

type Error: Error

The error type that can be returned if some error occurs during deserialization.

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Required methods

fn next_element_seed<T>(
    &mut self,
    seed: T
) -> Result<Option<T::Value>, Self::Error> where
    T: DeserializeSeed<'de>, 

This returns Ok(Some(value)) for the next value in the sequence, or Ok(None) if there are no more remaining items.

Deserialize implementations should typically use SeqAccess::next_element instead.

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Provided methods

fn next_element<T>(&mut self) -> Result<Option<T>, Self::Error> where
    T: Deserialize<'de>, 

This returns Ok(Some(value)) for the next value in the sequence, or Ok(None) if there are no more remaining items.

This method exists as a convenience for Deserialize implementations. SeqAccess implementations should not override the default behavior.

fn size_hint(&self) -> Option<usize>

Returns the number of elements remaining in the sequence, if known.

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Implementations on Foreign Types

impl<'de, 'a, A> SeqAccess<'de> for &'a mut A where
    A: SeqAccess<'de>, 

type Error = A::Error

fn next_element_seed<T>(
    &mut self,
    seed: T
) -> Result<Option<T::Value>, Self::Error> where
    T: DeserializeSeed<'de>, 

fn next_element<T>(&mut self) -> Result<Option<T>, Self::Error> where
    T: Deserialize<'de>, 

fn size_hint(&self) -> Option<usize>

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Implementors

impl<'de, I, E> SeqAccess<'de> for MapDeserializer<'de, I, E> where
    I: Iterator,
    I::Item: Pair,
    <I::Item as Pair>::First: IntoDeserializer<'de, E>,
    <I::Item as Pair>::Second: IntoDeserializer<'de, E>,
    E: Error, 

type Error = E

fn next_element_seed<T>(
    &mut self,
    seed: T
) -> Result<Option<T::Value>, Self::Error> where
    T: DeserializeSeed<'de>, 

fn size_hint(&self) -> Option<usize>

fn next_element<T>(&mut self) -> Result<Option<T>, Self::Error> where
    T: Deserialize<'de>, 

impl<'de, I, T, E> SeqAccess<'de> for SeqDeserializer<I, E> where
    I: Iterator<Item = T>,
    T: IntoDeserializer<'de, E>,
    E: Error, 

type Error = E

fn next_element_seed<V>(
    &mut self,
    seed: V
) -> Result<Option<V::Value>, Self::Error> where
    V: DeserializeSeed<'de>, 

fn size_hint(&self) -> Option<usize>

fn next_element<T>(&mut self) -> Result<Option<T>, Self::Error> where
    T: Deserialize<'de>, 

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