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>>> 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<NonZero<i128>>> 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<NonZero<i16>>> 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<NonZero<i32>>> 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<NonZero<i64>>> 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<NonZero<i8>>> 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<NonZero<isize>>> 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<NonZero<u128>>> 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<NonZero<u16>>> 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<NonZero<u32>>> 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<NonZero<u64>>> 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<NonZero<u8>>> 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<NonZero<usize>>> 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>>, 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<NonZero<i128>>, 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<NonZero<i16>>, 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<NonZero<i32>>, 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<NonZero<isize>>, 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<NonZero<i64>>, 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<NonZero<i8>>, 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<NonZero<u128>>, 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<NonZero<u16>>, 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<NonZero<u32>>, 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<NonZero<usize>>, 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<NonZero<u64>>, 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<NonZero<u8>>, 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>>, 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<NonZero<i128>>, 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<NonZero<i16>>, 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<NonZero<i32>>, 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<NonZero<i64>>, 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<NonZero<i8>>, 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<NonZero<isize>>, 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<NonZero<u128>>, 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<NonZero<u16>>, 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<NonZero<u32>>, 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<NonZero<u64>>, 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<NonZero<u8>>, 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<NonZero<usize>>, S> for Niche

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

Serializes the field type F using the given serializer.