Enum WireLen 

pub enum WireLen<T> {
    Auto,
    Set(T),
}

A wire length/count field: Auto-derived by default, or an explicit Set override. See the module docs.

Variants

Auto

Derive this length from its declared target when the message is encoded.

Set(T)

Write exactly this value — a deliberate override, or the value read on decode.

Implementations

impl<T> WireLen<T>

pub fn auto() -> Self

An auto-deriving length (the default). Equivalent to WireLen::Auto.

pub fn set(value: T) -> Self

A pinned, explicit length. Equivalent to WireLen::Set — the dual-use override.

pub fn is_auto(&self) -> bool

Whether this length auto-derives (has no explicit value yet).

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

The explicit value, or None if it auto-derives. A decoded WireLen is always Some; a freshly-built Auto is None until resolved at encode.

impl<T: CountPrefix> WireLen<T>

pub fn to_count(&self) -> usize

The value as a usize element count (for #[br(count = …)] on the decode side, where a WireLen is always Set). An unresolved Auto reads as 0 (it never occurs on decode).

pub fn resolve_count(&self, len: usize) -> Result<Self, BitError>

Resolve an Auto to the checked count of len (leaving a Set untouched) — the encode-time derivation the macro emits.

Errors

BitError if len exceeds T’s range (a checked conversion, never a truncation).

Trait Implementations

impl<T: Bits> BitDecode for WireLen<T>

fn bit_decode<S: Source>(r: &mut S) -> Result<Self, BitError>

Decodes Self from any Source, advancing its cursor.

impl<T: Bits> BitEncode for WireLen<T>

fn bit_encode<K: Sink>(&self, w: &mut K) -> Result<(), BitError>

Encodes self verbatim into any Sink, advancing its cursor.

const LAYOUT: Layout = _

The message’s bit/byte order, used to size a fresh BitWriter when encoding to a Vec/writer. The derive sets it from the struct’s declared bit_order/bytes; a hand-written impl that only ever encodes into a caller-supplied Sink can leave the default.

fn canonical_bit_encode<K: Sink>(&self, w: &mut K) -> Result<(), BitError>

Encodes self’s canonical form into any Sink: reserved fields as their spec value, calc fields recomputed. Defaults to bit_encode (verbatim == canonical) for messages with no reserved/calc field.

fn encode_mode(&self) -> EncodeMode

The form EncodeExt::encode writes for this value. Defaults to EncodeMode::Verbatim; a #[bin] message with a reserved/calc field carries a settable encode_mode and overrides this to return it.

impl<T: Clone> Clone for WireLen<T>

fn clone(&self) -> WireLen<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Copy> Copy for WireLen<T>

impl<T: Debug> Debug for WireLen<T>

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

Formats the value using the given formatter.

impl<T> Default for WireLen<T>

fn default() -> WireLen<T>

Returns the “default value” for a type.

impl<T: Eq> Eq for WireLen<T>

impl<T: Bits> FixedBitLen for WireLen<T>

A WireLen<T> occupies exactly T’s width, so it stays a fixed-width field (a DNS header with WireLen<u16> counts is still 12 bytes).

const BIT_LEN: u32 = <T as Bits>::BITS

Total encoded width of the message in bits — the sum of its fields’ widths.

impl<T: Hash> Hash for WireLen<T>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: PartialEq> PartialEq for WireLen<T>

fn eq(&self, other: &WireLen<T>) -> 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: PartialEq> StructuralPartialEq for WireLen<T>