Struct FromIntoIterator 

pub struct FromIntoIterator<Coll, Len>(/* private fields */);

A generic sequence schema for custom collections that implement FromIterator (for reading) and whose references implement IntoIterator with an ExactSizeIterator (for writing).

Works for both element sequences and key-value maps:

• For element collections (sets, ordered sets, etc.) whose reference iterators yield &T, the schema for T is used directly.
• For map-like collections whose reference iterators yield (&K, &V) pairs, the pair itself acts as the schema (automatically satisfied when K and V implement SchemaWrite<C>).

Intended for external collection types that cannot have a dedicated schema impl added directly. Unlike Vec, VecDeque, and BinaryHeap, this container relies on the collection’s FromIterator impl rather than writing directly into preallocated memory.

For manual SchemaWrite implementations that emit a sequence from an ad-hoc iterator rather than a concrete collection, see encode_from_iter_prealloc_check (and its check-skipping counterpart encode_from_iter).

Allocation efficiency

During deserialization, the iterator passed to FromIterator has a precise size_hint matching the number of elements produced, unless a read error is encountered. Collections whose FromIterator implementation uses the size hint to preallocate capacity will allocate optimally. Collections that do not use it will not benefit.

Examples

use some_crate::{IndexSet, MyMap};
use wincode::{SchemaRead, SchemaWrite, containers::FromIntoIterator, len::BincodeLen};

#[derive(SchemaRead, SchemaWrite)]
struct MyData {
    #[wincode(with = "FromIntoIterator<IndexSet<u32>, BincodeLen>")]
    items: IndexSet<u32>,
    #[wincode(with = "FromIntoIterator<MyMap<u32, u64>, BincodeLen>")]
    map: MyMap<u32, u64>,
}

Trait Implementations

impl<'de, Coll, Len, C: ConfigCore> SchemaRead<'de, C> for FromIntoIterator<Coll, Len>

where Len: SeqLen<C>, Coll: IntoIterator<Item: SchemaRead<'de, C>> + FromIterator<<Coll::Item as SchemaRead<'de, C>>::Dst>,

type Dst = Coll

fn read(reader: impl Reader<'de>, dst: &mut MaybeUninit<Coll>) -> ReadResult<()>

Read into dst from reader.

const TYPE_META: TypeMeta = TypeMeta::Dynamic

Metadata about the type’s serialization.

fn get(reader: impl Reader<'de>) -> ReadResult<Self::Dst>

Read Self::Dst from reader into a new Self::Dst.

impl<Coll, Len, C: ConfigCore> SchemaWrite<C> for FromIntoIterator<Coll, Len>

where Len: SeqLen<C>, Coll: IntoIterator, for<'a> &'a Coll: IntoIterator<Item: SchemaWrite<C>, IntoIter: ExactSizeIterator>, for<'a> <&'a Coll as IntoIterator>::Item: Borrow<<<&'a Coll as IntoIterator>::Item as SchemaWrite<C>>::Src>,

type Src = Coll

fn size_of(src: &Coll) -> WriteResult<usize>

Get the serialized size of Self::Src.

fn write(writer: impl Writer, src: &Coll) -> WriteResult<()>

Write Self::Src to writer.

const TYPE_META: TypeMeta = TypeMeta::Dynamic

Metadata about the type’s serialization.