serde_encom 0.4.0

use crate::des::{deserializer::Deserializer, read::Read};
use crate::error::{Error, Result};
use serde::de::{self, Unexpected};

pub(crate) struct UnitVariantAccess<'a, R: 'a> {
    de: &'a mut Deserializer<R>,
}

impl<'a, R: 'a> UnitVariantAccess<'a, R> {
    pub(crate) fn new(de: &'a mut Deserializer<R>) -> Self {
        UnitVariantAccess { de }
    }
}

impl<'de, 'a, R: Read<'de> + 'a> de::EnumAccess<'de> for UnitVariantAccess<'a, R> {
    type Error = Error;
    type Variant = Self;

    fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self)>
    where
        V: de::DeserializeSeed<'de>,
    {
        let variant = seed.deserialize(&mut *self.de)?;
        Ok((variant, self))
    }
}

impl<'de, 'a, R: Read<'de> + 'a> de::VariantAccess<'de> for UnitVariantAccess<'a, R> {
    type Error = Error;

    #[inline]
    fn unit_variant(self) -> Result<()> {
        Ok(())
    }

    fn newtype_variant_seed<T>(self, _seed: T) -> Result<T::Value>
    where
        T: de::DeserializeSeed<'de>,
    {
        Err(de::Error::invalid_type(
            Unexpected::UnitVariant,
            &"newtype variant",
        ))
    }

    fn tuple_variant<V>(self, _len: usize, _visitor: V) -> Result<V::Value>
    where
        V: de::Visitor<'de>,
    {
        Err(de::Error::invalid_type(
            Unexpected::UnitVariant,
            &"tuple variant",
        ))
    }

    fn struct_variant<V>(self, _fields: &'static [&'static str], _visitor: V) -> Result<V::Value>
    where
        V: de::Visitor<'de>,
    {
        Err(de::Error::invalid_type(
            Unexpected::UnitVariant,
            &"struct variant",
        ))
    }
}