Enum ScalarDelta 

pub enum ScalarDelta<T> {
    Unchanged,
    Changed(T),
}

This type exists as a workaround for the serde data model being unable to distinguish between Some(None) and None in serialized bytes. It is, in nearly every respect, Option<T>, just with some more semantic clarity. You may freely convert between this and Option<T> using From::from or Into::into.

Variants

Unchanged

The value was not altered, use the old value.

Changed(T)

The value was altered, here is the new value.

Implementations

impl<T> ScalarDelta<T>

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

Convenient shorthand for converting to Option.

pub fn is_unchanged(&self) -> bool

Returns true if this contains no change.

pub fn is_changed(&self) -> bool

Returns true if this contains a change.

Trait Implementations

impl<T: Clone> Clone for ScalarDelta<T>

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

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Copy> Copy for ScalarDelta<T>

impl<T: Debug> Debug for ScalarDelta<T>

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

Formats the value using the given formatter.

impl<T> Default for ScalarDelta<T>

fn default() -> ScalarDelta<T>

Returns the “default value” for a type.

impl<'de, T> Deserialize<'de> for ScalarDelta<T>

where T: Deserialize<'de>,

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<T: Eq> Eq for ScalarDelta<T>

impl<T> From<Option<T>> for ScalarDelta<T>

fn from(value: Option<T>) -> Self

Converts to this type from the input type.

impl<T> From<ScalarDelta<T>> for Option<T>

fn from(value: ScalarDelta<T>) -> Self

Converts to this type from the input type.

impl<T: Hash> Hash for ScalarDelta<T>

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<T: Ord> Ord for ScalarDelta<T>

fn cmp(&self, other: &ScalarDelta<T>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<T: PartialEq> PartialEq for ScalarDelta<T>

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

Equality operator ==.

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

Inequality operator !=.

impl<T: PartialOrd> PartialOrd for ScalarDelta<T>

fn partial_cmp(&self, other: &ScalarDelta<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T> Serialize for ScalarDelta<T>

where T: Serialize,

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

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