Struct Len 

pub struct Len(pub usize);

Length context.

Used for providing an already read or in-memory length value to a type that would otherwise read it from a Reader.

Examples

struct Header {
    data_len: u8,
}

struct Data {
    header: Header,
    data: Vec<u8>,
}

unsafe impl<C: Config> SchemaWrite<C> for Data {
    type Src = Self;

    fn size_of(src: &Self::Src) -> WriteResult<usize> {
        Ok(1 + src.data.len())
    }

    fn write(mut writer: impl Writer, src: &Self::Src) -> WriteResult<()> {
        writer.write(&[src.header.data_len])?;
        writer.write(&src.data)?;
        Ok(())
    }
}

unsafe impl<'de, C: Config> SchemaRead<'de, C> for Data {
    type Dst = Self;

    fn read(
        mut reader: impl Reader<'de>,
        dst: &mut MaybeUninit<Self::Dst>,
    ) -> ReadResult<()> {
        let len = reader.take_byte()?;

        let data = <Vec<u8> as SchemaReadContext<C, _>>::get_with_context(
            context::Len(len as usize),
            reader
        )?;

        dst.write(Self {
            header: Header { data_len: len },
            data,
        });

        Ok(())
    }
}

let data = Data {
    header: Header { data_len: 8},
    data: vec![0u8; 8],
};
let bytes = wincode::serialize(&data).unwrap();
let deserialized = wincode::deserialize(&bytes).unwrap();
assert_eq!(data, deserialized);

Tuple Fields

0: usize

Trait Implementations

impl Clone for Len

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Len

impl Debug for Len

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

Formats the value using the given formatter.

impl Eq for Len

impl Ord for Len

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.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for Len

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialOrd for Len

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<'de, T, C: ConfigCore> SchemaReadContext<'de, C, Len> for Vec<T>

where T: SchemaRead<'de, C>,

Available on crate feature alloc only.

type Dst = Vec<<T as SchemaRead<'de, C>>::Dst>

fn read_with_context( ctx: Len, reader: impl Reader<'de>, dst: &mut MaybeUninit<Self::Dst>, ) -> ReadResult<()>

Read into dst from reader with context.

const TYPE_META: TypeMeta = TypeMeta::Dynamic

Metadata about the type’s serialization.

fn get_with_context(ctx: Ctx, reader: impl Reader<'de>) -> ReadResult<Self::Dst>

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

impl<'de, C: ConfigCore> SchemaReadContext<'de, C, Len> for &'de str

type Dst = &'de str

fn read_with_context( context::Len: Len, reader: impl Reader<'de>, dst: &mut MaybeUninit<Self::Dst>, ) -> ReadResult<()>

Read into dst from reader with context.

const TYPE_META: TypeMeta = TypeMeta::Dynamic

Metadata about the type’s serialization.

fn get_with_context(ctx: Ctx, reader: impl Reader<'de>) -> ReadResult<Self::Dst>

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

impl<'de, C: Config> SchemaReadContext<'de, C, Len> for String

Available on crate feature alloc only.

type Dst = String

fn read_with_context( ctx: Len, reader: impl Reader<'de>, dst: &mut MaybeUninit<Self::Dst>, ) -> ReadResult<()>

Read into dst from reader with context.

const TYPE_META: TypeMeta = TypeMeta::Dynamic

Metadata about the type’s serialization.

fn get_with_context(ctx: Ctx, reader: impl Reader<'de>) -> ReadResult<Self::Dst>

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

impl<'de, T, C: ConfigCore> SchemaReadContext<'de, C, Len> for &'de [T]

where T: SchemaRead<'de, C> + ZeroCopy<C>,

const TYPE_META: TypeMeta

Metadata about the type’s serialization.

type Dst = &'de [<T as SchemaRead<'de, C>>::Dst]

fn read_with_context( context::Len: Len, reader: impl Reader<'de>, dst: &mut MaybeUninit<Self::Dst>, ) -> ReadResult<()>

Read into dst from reader with context.

fn get_with_context(ctx: Ctx, reader: impl Reader<'de>) -> ReadResult<Self::Dst>

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

impl<'de, T, C: ConfigCore> SchemaReadContext<'de, C, Len> for Cow<'de, [T]>

where [T]: ToOwned, &'de [T]: SchemaReadContext<'de, C, Len, Dst = &'de [T]>, <[T] as ToOwned>::Owned: SchemaReadContext<'de, C, Len, Dst = <[T] as ToOwned>::Owned>,

Available on crate feature alloc only.

type Dst = Cow<'de, [T]>

fn read_with_context( ctx: Len, reader: impl Reader<'de>, dst: &mut MaybeUninit<Self::Dst>, ) -> ReadResult<()>

Read into dst from reader with context.

const TYPE_META: TypeMeta = TypeMeta::Dynamic

Metadata about the type’s serialization.

fn get_with_context(ctx: Ctx, reader: impl Reader<'de>) -> ReadResult<Self::Dst>

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

impl StructuralPartialEq for Len