Enum contrie::ExistingOrNew

pub enum ExistingOrNew<T> {
    Existing(T),
    New(T),
}

A simple enum to make a distinction if the returned value is an already existing one or a newly created instance.

As it dereferences to the held value, it acts almost as the value T in many circumstances. Otherwise it can also be extracted.

Variants

Existing(T)

The entry already existed.

New(T)

A new entry had to be inserted to satisfy the request.

Methods

impl<T> ExistingOrNew<T>

pub fn into_inner(self) -> T

Extracts the inner value.

pub fn map<U, F: FnOnce(T) -> U>(self, f: F) -> ExistingOrNew<U>

Applies a transformation to the value.

This applies the function to the inner value, but preserves the information if it was a new or existing one.

pub fn is_new(&self) -> bool

Checks if the value was newly created one.

Trait Implementations

impl<T: PartialEq> PartialEq<ExistingOrNew<T>> for ExistingOrNew<T>

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

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &ExistingOrNew<T>) -> bool

This method tests for !=.

impl<T: Clone> Clone for ExistingOrNew<T>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: PartialOrd> PartialOrd<ExistingOrNew<T>> for ExistingOrNew<T>

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

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

fn lt(&self, other: &ExistingOrNew<T>) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &ExistingOrNew<T>) -> bool

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

fn gt(&self, other: &ExistingOrNew<T>) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &ExistingOrNew<T>) -> bool

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

impl<T: Eq> Eq for ExistingOrNew<T>

impl<T: Ord> Ord for ExistingOrNew<T>

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

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

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

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl<T: Copy> Copy for ExistingOrNew<T>

impl<T> DerefMut for ExistingOrNew<T>

fn deref_mut(&mut self) -> &mut T

Mutably dereferences the value.

impl<T> Deref for ExistingOrNew<T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<T: Debug> Debug for ExistingOrNew<T>

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

Formats the value using the given formatter.

impl<T: Hash> Hash for ExistingOrNew<T>

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

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].