fn visit_unit<E>(self) -> Result<Self::Value, E>
    where
        E: Error,
    {
        Err(Error::invalid_type(Unexpected::Unit, &self))
    }
/// The input contains a unit `()`.
///
/// The default implementation fails with a type error.
The input contains a unit `()`.
The default implementation fails with a type error.
The input contains a unit ` () ` . The default implementation fails with a type error .
fn visit_unit<E>(self) -> Result<Self::Value, E>
    where
        E: Error,
    {
        Err(Error::invalid_type(Unexpected::Unit, &self))
    }
fn visit_unit < E > ( self ) -> Result < Self :: Value , E > where E : Error , { Err ( Error :: invalid_type ( Unexpected :: Unit , & self ) ) }
The input contains a unit `()`.
The input contains a unit ` () ` .
self
self