Enum Necessity 

pub enum Necessity {
    Unmarked,
    Required,
    Optional,
}

Whether a field is marked as required or optional.

Variants

Unmarked

No marker.

Required

Marked with an asterisk, and the control gets required.

Optional

Marked “(optional)”.

Trait Implementations

impl Clone for Necessity

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Necessity

impl Debug for Necessity

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

Formats the value using the given formatter.

impl Default for Necessity

fn default() -> Self

Returns the “default value” for a type.

impl Eq for Necessity

impl Hash for Necessity

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 Necessity

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Necessity