Struct rkyv::with::Niche

pub struct Niche;

A wrapper that niches some type combinations.

A common type combination is Option<Box<T>>. By using a null pointer, the archived version can save some space on-disk.

Example

use core::mem::size_of;
use rkyv::{Archive, Archived, with::Niche};

#[derive(Archive)]
struct BasicExample {
    value: Option<Box<str>>,
}

#[derive(Archive)]
struct NichedExample {
    #[with(Niche)]
    value: Option<Box<str>>,
}

assert!(size_of::<Archived<BasicExample>>() > size_of::<Archived<NichedExample>>());

Trait Implementations

impl<T: ArchiveUnsized + ?Sized> ArchiveWith<Option<Box<T, Global>>> for Niche where
    ArchivedMetadata<T>: Default, 

type Archived = ArchivedOptionBox<<T as ArchiveUnsized>::Archived>

The archived type of a With<F, Self>.

type Resolver = OptionBoxResolver<<T as ArchiveUnsized>::MetadataResolver>

The resolver of a With<F, Self>.

unsafe fn resolve_with(
    field: &Option<Box<T>>,
    pos: usize,
    resolver: Self::Resolver,
    out: *mut Self::Archived
)

Resolves the archived type using a reference to the field type F.

impl ArchiveWith<Option<NonZeroI128>> for Niche

type Archived = ArchivedOptionNonZeroI128

The archived type of a With<F, Self>.

type Resolver = ()

The resolver of a With<F, Self>.

unsafe fn resolve_with(
    field: &Option<NonZeroI128>,
    _: usize,
    _: Self::Resolver,
    out: *mut Self::Archived
)

Resolves the archived type using a reference to the field type F.

impl ArchiveWith<Option<NonZeroI16>> for Niche

type Archived = ArchivedOptionNonZeroI16

The archived type of a With<F, Self>.

type Resolver = ()

The resolver of a With<F, Self>.

unsafe fn resolve_with(
    field: &Option<NonZeroI16>,
    _: usize,
    _: Self::Resolver,
    out: *mut Self::Archived
)

Resolves the archived type using a reference to the field type F.

impl ArchiveWith<Option<NonZeroI32>> for Niche

type Archived = ArchivedOptionNonZeroI32

The archived type of a With<F, Self>.

type Resolver = ()

The resolver of a With<F, Self>.

unsafe fn resolve_with(
    field: &Option<NonZeroI32>,
    _: usize,
    _: Self::Resolver,
    out: *mut Self::Archived
)

Resolves the archived type using a reference to the field type F.

impl ArchiveWith<Option<NonZeroI64>> for Niche

type Archived = ArchivedOptionNonZeroI64

The archived type of a With<F, Self>.

type Resolver = ()

The resolver of a With<F, Self>.

unsafe fn resolve_with(
    field: &Option<NonZeroI64>,
    _: usize,
    _: Self::Resolver,
    out: *mut Self::Archived
)

Resolves the archived type using a reference to the field type F.

impl ArchiveWith<Option<NonZeroI8>> for Niche

type Archived = ArchivedOptionNonZeroI8

The archived type of a With<F, Self>.

type Resolver = ()

The resolver of a With<F, Self>.

unsafe fn resolve_with(
    field: &Option<NonZeroI8>,
    _: usize,
    _: Self::Resolver,
    out: *mut Self::Archived
)

Resolves the archived type using a reference to the field type F.

impl ArchiveWith<Option<NonZeroIsize>> for Niche

type Archived = ArchivedOptionNonZeroI32

The archived type of a With<F, Self>.

type Resolver = ()

The resolver of a With<F, Self>.

unsafe fn resolve_with(
    field: &Option<NonZeroIsize>,
    _: usize,
    _: Self::Resolver,
    out: *mut Self::Archived
)

Resolves the archived type using a reference to the field type F.

impl ArchiveWith<Option<NonZeroU128>> for Niche

type Archived = ArchivedOptionNonZeroU128

The archived type of a With<F, Self>.

type Resolver = ()

The resolver of a With<F, Self>.

unsafe fn resolve_with(
    field: &Option<NonZeroU128>,
    _: usize,
    _: Self::Resolver,
    out: *mut Self::Archived
)

Resolves the archived type using a reference to the field type F.

impl ArchiveWith<Option<NonZeroU16>> for Niche

type Archived = ArchivedOptionNonZeroU16

The archived type of a With<F, Self>.

type Resolver = ()

The resolver of a With<F, Self>.

unsafe fn resolve_with(
    field: &Option<NonZeroU16>,
    _: usize,
    _: Self::Resolver,
    out: *mut Self::Archived
)

Resolves the archived type using a reference to the field type F.

impl ArchiveWith<Option<NonZeroU32>> for Niche

type Archived = ArchivedOptionNonZeroU32

The archived type of a With<F, Self>.

type Resolver = ()

The resolver of a With<F, Self>.

unsafe fn resolve_with(
    field: &Option<NonZeroU32>,
    _: usize,
    _: Self::Resolver,
    out: *mut Self::Archived
)

Resolves the archived type using a reference to the field type F.

impl ArchiveWith<Option<NonZeroU64>> for Niche

type Archived = ArchivedOptionNonZeroU64

The archived type of a With<F, Self>.

type Resolver = ()

The resolver of a With<F, Self>.

unsafe fn resolve_with(
    field: &Option<NonZeroU64>,
    _: usize,
    _: Self::Resolver,
    out: *mut Self::Archived
)

Resolves the archived type using a reference to the field type F.

impl ArchiveWith<Option<NonZeroU8>> for Niche

type Archived = ArchivedOptionNonZeroU8

The archived type of a With<F, Self>.

type Resolver = ()

The resolver of a With<F, Self>.

unsafe fn resolve_with(
    field: &Option<NonZeroU8>,
    _: usize,
    _: Self::Resolver,
    out: *mut Self::Archived
)

Resolves the archived type using a reference to the field type F.

impl ArchiveWith<Option<NonZeroUsize>> for Niche

type Archived = ArchivedOptionNonZeroU32

The archived type of a With<F, Self>.

type Resolver = ()

The resolver of a With<F, Self>.

unsafe fn resolve_with(
    field: &Option<NonZeroUsize>,
    _: usize,
    _: Self::Resolver,
    out: *mut Self::Archived
)

Resolves the archived type using a reference to the field type F.

impl Debug for Niche

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

Formats the value using the given formatter.

impl<T, D> DeserializeWith<ArchivedOptionBox<<T as ArchiveUnsized>::Archived>, Option<Box<T, Global>>, D> for Niche where
    T: ArchiveUnsized + ?Sized,
    T::Archived: DeserializeUnsized<T, D>,
    D: Fallible + ?Sized, 

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

Deserializes the field type F using the given deserializer.

impl<D: Fallible + ?Sized> DeserializeWith<ArchivedOptionNonZeroI128, Option<NonZeroI128>, D> for Niche

fn deserialize_with(
    field: &ArchivedOptionNonZeroI128,
    _: &mut D
) -> Result<Option<NonZeroI128>, D::Error>

Deserializes the field type F using the given deserializer.

impl<D: Fallible + ?Sized> DeserializeWith<ArchivedOptionNonZeroI16, Option<NonZeroI16>, D> for Niche

fn deserialize_with(
    field: &ArchivedOptionNonZeroI16,
    _: &mut D
) -> Result<Option<NonZeroI16>, D::Error>

Deserializes the field type F using the given deserializer.

impl<D: Fallible + ?Sized> DeserializeWith<ArchivedOptionNonZeroI32, Option<NonZeroI32>, D> for Niche

fn deserialize_with(
    field: &ArchivedOptionNonZeroI32,
    _: &mut D
) -> Result<Option<NonZeroI32>, D::Error>

Deserializes the field type F using the given deserializer.

impl<D: Fallible + ?Sized> DeserializeWith<ArchivedOptionNonZeroI32, Option<NonZeroIsize>, D> for Niche

fn deserialize_with(
    field: &ArchivedOptionNonZeroI32,
    _: &mut D
) -> Result<Option<NonZeroIsize>, D::Error>

Deserializes the field type F using the given deserializer.

impl<D: Fallible + ?Sized> DeserializeWith<ArchivedOptionNonZeroI64, Option<NonZeroI64>, D> for Niche

fn deserialize_with(
    field: &ArchivedOptionNonZeroI64,
    _: &mut D
) -> Result<Option<NonZeroI64>, D::Error>

Deserializes the field type F using the given deserializer.

impl<D: Fallible + ?Sized> DeserializeWith<ArchivedOptionNonZeroI8, Option<NonZeroI8>, D> for Niche

fn deserialize_with(
    field: &ArchivedOptionNonZeroI8,
    _: &mut D
) -> Result<Option<NonZeroI8>, D::Error>

Deserializes the field type F using the given deserializer.

impl<D: Fallible + ?Sized> DeserializeWith<ArchivedOptionNonZeroU128, Option<NonZeroU128>, D> for Niche

fn deserialize_with(
    field: &ArchivedOptionNonZeroU128,
    _: &mut D
) -> Result<Option<NonZeroU128>, D::Error>

Deserializes the field type F using the given deserializer.

impl<D: Fallible + ?Sized> DeserializeWith<ArchivedOptionNonZeroU16, Option<NonZeroU16>, D> for Niche

fn deserialize_with(
    field: &ArchivedOptionNonZeroU16,
    _: &mut D
) -> Result<Option<NonZeroU16>, D::Error>

Deserializes the field type F using the given deserializer.

impl<D: Fallible + ?Sized> DeserializeWith<ArchivedOptionNonZeroU32, Option<NonZeroU32>, D> for Niche

fn deserialize_with(
    field: &ArchivedOptionNonZeroU32,
    _: &mut D
) -> Result<Option<NonZeroU32>, D::Error>

Deserializes the field type F using the given deserializer.

impl<D: Fallible + ?Sized> DeserializeWith<ArchivedOptionNonZeroU32, Option<NonZeroUsize>, D> for Niche

fn deserialize_with(
    field: &ArchivedOptionNonZeroU32,
    _: &mut D
) -> Result<Option<NonZeroUsize>, D::Error>

Deserializes the field type F using the given deserializer.

impl<D: Fallible + ?Sized> DeserializeWith<ArchivedOptionNonZeroU64, Option<NonZeroU64>, D> for Niche

fn deserialize_with(
    field: &ArchivedOptionNonZeroU64,
    _: &mut D
) -> Result<Option<NonZeroU64>, D::Error>

Deserializes the field type F using the given deserializer.

impl<D: Fallible + ?Sized> DeserializeWith<ArchivedOptionNonZeroU8, Option<NonZeroU8>, D> for Niche

fn deserialize_with(
    field: &ArchivedOptionNonZeroU8,
    _: &mut D
) -> Result<Option<NonZeroU8>, D::Error>

Deserializes the field type F using the given deserializer.

impl<T, S> SerializeWith<Option<Box<T, Global>>, S> for Niche where
    T: SerializeUnsized<S> + ?Sized,
    S: Serializer + ?Sized,
    ArchivedMetadata<T>: Default, 

fn serialize_with(
    field: &Option<Box<T>>,
    serializer: &mut S
) -> Result<Self::Resolver, S::Error>

Serializes the field type F using the given serializer.

impl<S: Fallible + ?Sized> SerializeWith<Option<NonZeroI128>, S> for Niche

fn serialize_with(
    _: &Option<NonZeroI128>,
    _: &mut S
) -> Result<Self::Resolver, S::Error>

Serializes the field type F using the given serializer.

impl<S: Fallible + ?Sized> SerializeWith<Option<NonZeroI16>, S> for Niche

fn serialize_with(
    _: &Option<NonZeroI16>,
    _: &mut S
) -> Result<Self::Resolver, S::Error>

Serializes the field type F using the given serializer.

impl<S: Fallible + ?Sized> SerializeWith<Option<NonZeroI32>, S> for Niche

fn serialize_with(
    _: &Option<NonZeroI32>,
    _: &mut S
) -> Result<Self::Resolver, S::Error>

Serializes the field type F using the given serializer.

impl<S: Fallible + ?Sized> SerializeWith<Option<NonZeroI64>, S> for Niche

fn serialize_with(
    _: &Option<NonZeroI64>,
    _: &mut S
) -> Result<Self::Resolver, S::Error>

Serializes the field type F using the given serializer.

impl<S: Fallible + ?Sized> SerializeWith<Option<NonZeroI8>, S> for Niche

fn serialize_with(
    _: &Option<NonZeroI8>,
    _: &mut S
) -> Result<Self::Resolver, S::Error>

Serializes the field type F using the given serializer.

impl<S: Fallible + ?Sized> SerializeWith<Option<NonZeroIsize>, S> for Niche

fn serialize_with(
    _: &Option<NonZeroIsize>,
    _: &mut S
) -> Result<Self::Resolver, S::Error>

Serializes the field type F using the given serializer.

impl<S: Fallible + ?Sized> SerializeWith<Option<NonZeroU128>, S> for Niche

fn serialize_with(
    _: &Option<NonZeroU128>,
    _: &mut S
) -> Result<Self::Resolver, S::Error>

Serializes the field type F using the given serializer.

impl<S: Fallible + ?Sized> SerializeWith<Option<NonZeroU16>, S> for Niche

fn serialize_with(
    _: &Option<NonZeroU16>,
    _: &mut S
) -> Result<Self::Resolver, S::Error>

Serializes the field type F using the given serializer.

impl<S: Fallible + ?Sized> SerializeWith<Option<NonZeroU32>, S> for Niche

fn serialize_with(
    _: &Option<NonZeroU32>,
    _: &mut S
) -> Result<Self::Resolver, S::Error>

Serializes the field type F using the given serializer.

impl<S: Fallible + ?Sized> SerializeWith<Option<NonZeroU64>, S> for Niche

fn serialize_with(
    _: &Option<NonZeroU64>,
    _: &mut S
) -> Result<Self::Resolver, S::Error>

Serializes the field type F using the given serializer.

impl<S: Fallible + ?Sized> SerializeWith<Option<NonZeroU8>, S> for Niche

fn serialize_with(
    _: &Option<NonZeroU8>,
    _: &mut S
) -> Result<Self::Resolver, S::Error>

Serializes the field type F using the given serializer.

impl<S: Fallible + ?Sized> SerializeWith<Option<NonZeroUsize>, S> for Niche

fn serialize_with(
    _: &Option<NonZeroUsize>,
    _: &mut S
) -> Result<Self::Resolver, S::Error>

Serializes the field type F using the given serializer.