Struct Changeable 

pub struct Changeable<T> {
    pub from: Tracked<T>,
    pub to: Tracked<T>,
}

Represents a changeable value.

The from or to values are Tracked values, so the following cases mean the value is unchanged:

• Both values are Tracked::None
• Both values are Tracked::Known(t), and both ts are equal.

When either value is Tracked::Unknown, then its Equality is [Unknown].

Design Note

This is deliberately called Changeable instead of Change, because Change implies there is a change, whereas Changeable means there may be one.

Fields

from: Tracked<T>

Current value.

to: Tracked<T>

Next value.

Implementations

impl<T> Changeable<T>

where T: MaybeEq,

pub fn new(from: Tracked<T>, to: Tracked<T>) -> Self

Returns a new Changeable value.

See Changeable::known if both values are known.

pub fn known(from: T, to: T) -> Self

Returns a new Changeable value.

See Changeable::known if both values are known.

pub fn equality(&self) -> Equality

Returns the equality of the from and to values.

Trait Implementations

impl<T: Clone> Clone for Changeable<T>

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

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for Changeable<T>

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

Formats the value using the given formatter.

impl<'de, T> Deserialize<'de> for Changeable<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: PartialEq> PartialEq for Changeable<T>

fn eq(&self, other: &Changeable<T>) -> 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<T> Serialize for Changeable<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: Eq> Eq for Changeable<T>

impl<T> StructuralPartialEq for Changeable<T>