Struct NichedOption 

pub struct NichedOption<T, N: ?Sized> { /* private fields */ }

A niched ArchivedOption<T>.

It has the same layout as T, and thus uses less space by storing the None variant in a custom way based on N.

Implementations

impl<T, N: Niching<T> + ?Sized> NichedOption<T, N>

pub fn is_none(&self) -> bool

Returns true if the option is a None value.

pub fn is_some(&self) -> bool

Returns true if the option is a Some value.

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

Converts to an Option<&T>.

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

Converts to an Option<&mut T>.

pub fn as_seal(this: Seal<'_, Self>) -> Option<Seal<'_, T>>

Converts from Seal<'_, NichedOption<T, N>> to Option<Seal<'_, T>>.

pub fn iter(&self) -> Iter<&T>

Returns an iterator over the possibly-contained value.

pub fn iter_mut(&mut self) -> Iter<&mut T>

Returns an iterator over the mutable possibly-contained value.

pub fn iter_seal(this: Seal<'_, Self>) -> Iter<Seal<'_, T>>

Returns an iterator over the sealed possibly-contained value.

pub fn resolve_from_option<U>( option: Option<&U>, resolver: Option<U::Resolver>, out: Place<Self>, )

where U: Archive<Archived = T>,

Resolves a NichedOption<U::Archived, N> from an Option<&U>.

pub fn serialize_from_option<U, S>( option: Option<&U>, serializer: &mut S, ) -> Result<Option<U::Resolver>, S::Error>

where U: Serialize<S, Archived = T>, S: Fallible + ?Sized,

Serializes a NichedOption<U::Archived, N> from an Option<&U>.

impl<T, N> NichedOption<T, N>

where T: Deref, N: Niching<T> + ?Sized,

pub fn as_deref(&self) -> Option<&<T as Deref>::Target>

Converts from &NichedOption<T, N> to Option<&T::Target>.

Trait Implementations

impl<T, N, C> CheckBytes<C> for NichedOption<T, N>

where T: CheckBytes<C>, N: Niching<T> + ?Sized, C: Fallible + ?Sized,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

Checks whether the given pointer points to a valid value within the given context.

impl<T, N> Debug for NichedOption<T, N>

where T: Debug, N: Niching<T> + ?Sized,

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

Formats the value using the given formatter.

impl<T, N, D> Deserialize<Option<T>, D> for NichedOption<T::Archived, N>

where T: Archive<Archived: Deserialize<T, D>>, N: Niching<T::Archived> + ?Sized, D: Fallible + ?Sized,

fn deserialize(&self, deserializer: &mut D) -> Result<Option<T>, D::Error>

Deserializes using the given deserializer

impl<T, D> DeserializeWith<NichedOption<<T as Archive>::Archived, DefaultNiche>, Option<T>, D> for DefaultNiche

where T: Archive<Archived: Deserialize<T, D>>, Self: Niching<T::Archived>, D: Fallible + ?Sized,

fn deserialize_with( field: &NichedOption<T::Archived, Self>, deserializer: &mut D, ) -> Result<Option<T>, D::Error>

Deserializes the field type F using the given deserializer.

impl<T, N, D> DeserializeWith<NichedOption<<T as Archive>::Archived, N>, Option<T>, D> for NicheInto<N>

where T: Archive<Archived: Deserialize<T, D>>, N: Niching<T::Archived> + ?Sized, D: Fallible + ?Sized,

fn deserialize_with( field: &NichedOption<T::Archived, N>, deserializer: &mut D, ) -> Result<Option<T>, D::Error>

Deserializes the field type F using the given deserializer.

impl<T, W, N, D> DeserializeWith<NichedOption<<W as ArchiveWith<T>>::Archived, N>, Option<T>, D> for MapNiche<W, N>

where W: ArchiveWith<T> + DeserializeWith<<W as ArchiveWith<T>>::Archived, T, D>, N: Niching<<W as ArchiveWith<T>>::Archived> + ?Sized, D: Fallible + ?Sized,

fn deserialize_with( field: &NichedOption<<W as ArchiveWith<T>>::Archived, N>, deserializer: &mut D, ) -> Result<Option<T>, D::Error>

Deserializes the field type F using the given deserializer.

impl<T, N> Ord for NichedOption<T, N>

where T: Ord, N: Niching<T> + ?Sized,

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, N, Rhs> PartialEq<Option<Rhs>> for NichedOption<T, N>

where T: PartialEq<Rhs>, N: Niching<T> + ?Sized,

fn eq(&self, other: &Option<Rhs>) -> 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, N> PartialEq for NichedOption<T, N>

where T: PartialEq, N: Niching<T> + ?Sized,

fn eq(&self, other: &Self) -> 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, N> PartialOrd for NichedOption<T, N>

where T: PartialOrd, N: Niching<T> + ?Sized,

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, N> Eq for NichedOption<T, N>

where T: Eq, N: Niching<T> + ?Sized,

impl<T, N: ?Sized> Portable for NichedOption<T, N>

where MaybeUninit<T>: Portable, PhantomData<N>: Portable,