Trait FromValueOptional 

pub trait FromValueOptional<'a>: FromValueOptionalSealed<'a> { }

Trait for types that implement FromValue and are Optional.

This trait is auto-implemented for the appropriate types and is sealed.

Implementors

impl<'a, T, C, E> FromValueOptional<'a> for T

where T: FromValue<'a, Checker = C>, C: ValueTypeChecker<Error = ValueTypeMismatchOrNoneError<E>>, E: Error + Send + Sized + 'static,