Trait serde::de::VariantVisitor

pub trait VariantVisitor {
    type Error: Error;
    fn visit_variant<V>(&mut self) -> Result<V, Self::Error>
    where
        V: Deserialize;
    fn visit_newtype<T>(&mut self) -> Result<T, Self::Error>
    where
        T: Deserialize;
    fn visit_tuple<V>(
        &mut self, 
        len: usize, 
        visitor: V
    ) -> Result<V::Value, Self::Error>
    where
        V: Visitor;
    fn visit_struct<V>(
        &mut self, 
        fields: &'static [&'static str], 
        visitor: V
    ) -> Result<V::Value, Self::Error>
    where
        V: Visitor;

    fn visit_unit(&mut self) -> Result<(), Self::Error> { ... }
}

VariantVisitor is a visitor that is created by the Deserializer and passed to the Deserialize in order to deserialize a specific enum variant.

Associated Types

type Error: Error

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

Required Methods

fn visit_variant<V>(&mut self) -> Result<V, Self::Error> where
    V: Deserialize, 

visit_variant is called to identify which variant to deserialize.

fn visit_newtype<T>(&mut self) -> Result<T, Self::Error> where
    T: Deserialize, 

visit_newtype is called when deserializing a variant with a single value. A good default is often to use the visit_tuple method to deserialize a (value,).

fn visit_tuple<V>(
    &mut self,
    len: usize,
    visitor: V
) -> Result<V::Value, Self::Error> where
    V: Visitor, 

visit_tuple is called when deserializing a tuple-like variant. If no tuple variants are expected, yield a Err(serde::de::Error::invalid_type(serde::de::Type::TupleVariant))

fn visit_struct<V>(
    &mut self,
    fields: &'static [&'static str],
    visitor: V
) -> Result<V::Value, Self::Error> where
    V: Visitor, 

visit_struct is called when deserializing a struct-like variant. If no struct variants are expected, yield a Err(serde::de::Error::invalid_type(serde::de::Type::StructVariant))

Provided Methods

fn visit_unit(&mut self) -> Result<(), Self::Error>

visit_unit is called when deserializing a variant with no values.

Implementors

• impl<'a, E> VariantVisitor for StrDeserializer<'a, E> where
    E: Error,  type Error = E;
• impl<'a, E> VariantVisitor for StringDeserializer<E> where
    E: Error,  type Error = E;
• impl<'a, E> VariantVisitor for CowStrDeserializer<'a, E> where
    E: Error,  type Error = E;
• impl<'a, T> VariantVisitor for &'a mut T where
    T: VariantVisitor,  type Error = T::Error;