Enum Presence 

pub enum Presence {
    Required,
    Optional,
    Constant,
}

Field presence indicator.

Variants

Required

Field is required and must have a value.

Optional

Field is optional and may be null.

Constant

Field has a constant value defined in the schema.

Implementations

impl Presence

pub fn parse(s: &str) -> Option<Self>

Parses presence from a string.

Trait Implementations

impl Clone for Presence

fn clone(&self) -> Presence

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Presence

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Presence

fn default() -> Presence

Returns the “default value” for a type.

impl Hash for Presence

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Presence

fn eq(&self, other: &Presence) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Presence

impl Eq for Presence

impl StructuralPartialEq for Presence