Struct TaggedEnumAccess

struct TaggedEnumAccess<'der, 'a, 'de> {
    parent: &'der mut Deserializer<'a, 'de>,
    variant: Variant,
    payload_already_consumed: bool,
}

EnumAccess + VariantAccess adapter for tagged enums.

deserialize_enum already consumed the outer {u8 variant_tag: payload} map header and the variant tag, resolved the matching Variant from the Sum, and handed both off to us. From here:

• EnumAccess::variant_seed yields the variant’s serde name (as a borrowed string) to the visitor — serde-derive’s __Field visitor for enums accepts identifiers as strings just like struct-field visitors do.
• The four VariantAccess methods dispatch on the kind the visitor asks for (which is driven by the Rust declaration, not the wire), and each reads the matching payload shape directly from parent:
  • unit — consume the trailing nil written by the encode-side serialize_unit.
  • newtype — pass the bare inner value through &mut *parent so any nested tagged types still recurse through the wrapper.
  • tuple — read the int-keyed payload map and reuse the TaggedTupleStructAccess buffering machinery; the variant’s payload Product carries the tag/position mapping.
  • struct — read the int-keyed payload map and reuse TaggedProductMapAccess; the variant’s payload Product carries the tag/field-name mapping.

Fields

parent: &'der mut Deserializer<'a, 'de>

variant: Variant

payload_already_consumed: bool

Set when deserialize_enum has already drained the wire payload — the only way to land here is the catch-all route, where the payload was discarded with IgnoredAny before visit_enum. The catch-all is always a unit variant per macro validation, so only unit_variant needs to consult this flag.

Trait Implementations

impl<'de, 'der, 'a> EnumAccess<'de> for TaggedEnumAccess<'der, 'a, 'de>

type Error = Error

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

type Variant = TaggedEnumAccess<'der, 'a, 'de>

The Visitor that will be used to deserialize the content of the enum variant.

fn variant_seed<V>( self, seed: V, ) -> Result<(V::Value, Self::Variant), Self::Error>

where V: DeserializeSeed<'de>,

variant is called to identify which variant to deserialize.

fn variant<V>(self) -> Result<(V, Self::Variant), Self::Error>

where V: Deserialize<'de>,

variant is called to identify which variant to deserialize.

impl<'de, 'der, 'a> VariantAccess<'de> for TaggedEnumAccess<'der, 'a, 'de>

type Error = Error

The error type that can be returned if some error occurs during deserialization. Must match the error type of our EnumAccess.

fn unit_variant(self) -> Result<(), Self::Error>

Called when deserializing a variant with no values.

fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value, Self::Error>

where T: DeserializeSeed<'de>,

Called when deserializing a variant with a single value.

fn tuple_variant<V>( self, _len: usize, visitor: V, ) -> Result<V::Value, Self::Error>

where V: Visitor<'de>,

Called when deserializing a tuple-like variant.

fn struct_variant<V>( self, _fields: &'static [&'static str], visitor: V, ) -> Result<V::Value, Self::Error>

where V: Visitor<'de>,

Called when deserializing a struct-like variant.

fn newtype_variant<T>(self) -> Result<T, Self::Error>

where T: Deserialize<'de>,

Called when deserializing a variant with a single value.