Enum Patch 

pub enum Patch<T> {
    Unchanged,
    Clear,
    Set(T),
}

One field’s requested change: leave it, clear it, or set it.

A three-state patch rather than Option<Option<T>> for the reason crate::projects::Patch and crate::bulk::patch::PatchValue are: “the caller did not mention this field” and “the caller asked to empty it” are different requests, and an Option cannot tell them apart. Clearing an optional field removes the key; clearing the required author produces an entry that validation refuses by name, rather than a silent blank.

Variants

Unchanged

Leave the field as it is.

Clear

Remove the value.

Set(T)

Replace the value.

Implementations

impl<T> Patch<T>

pub fn is_unchanged(&self) -> bool

Whether this patch leaves the field alone.

Trait Implementations

impl<T: Clone> Clone for Patch<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for Patch<T>

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

Formats the value using the given formatter.

impl<T> Default for Patch<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: Eq> Eq for Patch<T>

impl<T: PartialEq> PartialEq for Patch<T>

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

Equality operator ==.

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

Inequality operator !=.

impl<T: PartialEq> StructuralPartialEq for Patch<T>