Enum Sentinelled

pub enum Sentinelled<T> {
    Smallest,
    Normal(T),
    Largest,
}

Sentinelled<T> wraps type T to provide smallest (smaller than any normal T value) and largest (larger than ant normal T value) sentinel value for T.

Sentinel is a very common technique used to simplify tree/list/array algorithms. The main idea is to insert sentinel node to the beginning or/and the end, so that algorithms don’t need to handle complex edge cases.

Variants

Smallest

Normal(T)

Largest

Implementations

impl<T> Sentinelled<T>

pub fn is_smallest(&self) -> bool

Returns true if this is a Sentinelled::Smallest, otherwise false

pub fn is_normal(&self) -> bool

Returns true if this is a Sentinelled::Normal, otherwise false

pub fn as_normal_mut(&mut self) -> Option<&mut T>

Optionally returns mutable references to the inner fields if this is a Sentinelled::Normal, otherwise None

pub fn as_normal(&self) -> Option<&T>

Optionally returns references to the inner fields if this is a Sentinelled::Normal, otherwise None

pub fn into_normal(self) -> Result<T, Self>

Returns the inner fields if this is a Sentinelled::Normal, otherwise returns back the enum in the Err case of the result

pub fn is_largest(&self) -> bool

Returns true if this is a Sentinelled::Largest, otherwise false

impl<T> Sentinelled<T>

pub fn as_normal_expect(&self) -> &T

pub fn is_sentinel(&self) -> bool

pub fn cmp_by( &self, other: &Self, cmp_fn: impl FnOnce(&T, &T) -> Ordering, ) -> Ordering

pub fn map<U>(self, map_fn: impl FnOnce(T) -> U) -> Sentinelled<U>

Trait Implementations

impl<T: Clone> Clone for Sentinelled<T>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for Sentinelled<T>

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

Formats the value using the given formatter.

impl<T: EstimateSize> EstimateSize for Sentinelled<T>

fn estimated_heap_size(&self) -> usize

The estimated heap size of the current struct in bytes.

fn estimated_size(&self) -> usize

where Self: Sized,

The estimated total size of the current struct in bytes, including the estimated_heap_size and the size of Self.

impl<T> From<T> for Sentinelled<T>

fn from(inner: T) -> Self

Converts to this type from the input type.

impl<T> Ord for Sentinelled<T>

where T: Ord,

fn cmp(&self, other: &Self) -> 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 Sentinelled<T>

fn eq(&self, other: &Sentinelled<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> PartialOrd for Sentinelled<T>

where T: Ord,

fn partial_cmp(&self, other: &Self) -> 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: Eq> Eq for Sentinelled<T>

impl<T> StructuralPartialEq for Sentinelled<T>