fn visit_none<E>(self) -> Result<Self::Value, E>
    where
        E: Error,
    {
        Err(Error::invalid_type(Unexpected::Option, &self))
    }
/// The input contains an optional that is absent.
///
/// The default implementation fails with a type error.
The input contains an optional that is absent.
The default implementation fails with a type error.
The input contains an optional that is absent . The default implementation fails with a type error .
fn visit_none<E>(self) -> Result<Self::Value, E>
    where
        E: Error,
    {
        Err(Error::invalid_type(Unexpected::Option, &self))
    }
fn visit_none < E > ( self ) -> Result < Self :: Value , E > where E : Error , { Err ( Error :: invalid_type ( Unexpected :: Option , & self ) ) }
The input contains an optional that is absent.
The input contains an optional that is absent .
self
self