Trait zvariant::NoneValue

pub trait NoneValue {
    type NoneType;
    fn null_value() -> Self::NoneType;
}

Type that uses a special value to be used as none.

See Optional documentation for the rationale for this trait’s existence.

Caveats

Since use of default values as none is typical, this trait is implemented for all types that implement Default for convenience. Unfortunately, this means you can not implement this trait manually for types that implement Default.

Associated Types

type NoneType

Required methods

fn null_value() -> Self::NoneType

The none-equivalent value.

Implementors

impl<T> NoneValue for T where
    T: Default, 

type NoneType = Self