Enum Patch 

pub enum Patch<T> {
    Missing,
    Null,
    Value(T),
}

A field of a merge patch that may also be cleared: absent from the patch, set to null, or given a value.

With the serde feature, it deserializes null as Patch::Null and a value as Patch::Value; an absent field takes the default, Patch::Missing, so put #[serde(default)] on the struct (or the field). To document it with utoipa, give the field #[schema(value_type = Option<T>)]: a nullable T, as clients send it.

Variants

Missing

Absent from the patch: the field is left unchanged.

Null

Set to null: the field is cleared.

Value(T)

Given a value: the field is replaced.

Implementations

impl<T> Patch<T>

pub const fn is_missing(&self) -> bool

Whether the field is absent from the patch.

pub const fn is_null(&self) -> bool

Whether the field is set to null.

pub fn value(self) -> Option<T>

The value given, if any (None when absent or null).

pub const fn as_ref(&self) -> Patch<&T>

A reference to the value given, if any.

pub fn map<U>(self, f: impl FnOnce(T) -> U) -> Patch<U>

The patch with its value, if any, mapped by f.

pub fn try_map<U, E>( self, f: impl FnOnce(T) -> Result<U, E>, ) -> Result<Patch<U>, E>

The patch with its value, if any, mapped by the fallible f (e.g. parsing a value object), or f’s error.

Errors

Returns f’s error.

Trait Implementations

impl<T> Clone for Patch<T>

where T: Clone,

fn clone(&self) -> Patch<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T> Copy for Patch<T>

where T: Copy,

impl<T> Debug for Patch<T>

where T: Debug,

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

Formats the value using the given formatter.

impl<T> Default for Patch<T>

fn default() -> Patch<T>

Returns the “default value” for a type.

impl<T> Eq for Patch<T>

where T: Eq,

impl<T> Hash for Patch<T>

where T: Hash,

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

where __H: Hasher,

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<T> PartialEq for Patch<T>

where T: PartialEq,

fn eq(&self, other: &Patch<T>) -> bool

Equality operator ==.

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

Inequality operator !=.

impl<P, F> PatchField<Option<F>> for Patch<P>

where P: Into<F>,

fn apply_to(self, field: &mut Option<F>)

Apply the patch’s field to the model’s field.

impl<T> PatchKind for Patch<T>

const NULLABLE: bool = true

Whether a field of this kind may be set to null.

fn is_null(&self) -> bool

Whether this field is set to null.

impl<T> StructuralPartialEq for Patch<T>

where T: PartialEq,