Struct Context 

pub struct Context { /* private fields */ }

External information required to encode or decode a contextual value.

The initial context records whether the current field is present. This is intended for protocol fields described as Optional X, where no presence marker is encoded and the field’s presence must be known from its enclosing packet or data structure.

A Context does not consume or produce any bytes. The enclosing codec must derive it from already-known protocol state and pass it to ContextualCodec.

Examples

use mcproto_types::contextual::Context;

let has_signature = true; // Derived from an earlier packet field.
let context = Context::new(has_signature);
assert!(context.is_present());
assert!(!Context::absent().is_present());

Implementations

impl Context

pub const PRESENT: Self

Context for a field that is present on the wire.

pub const ABSENT: Self

Context for a field that occupies zero bytes on the wire.

pub const fn new(present: bool) -> Self

Creates a context from a presence condition determined by the enclosing protocol structure.

pub const fn present() -> Self

Creates context for a field that is present on the wire.

pub const fn absent() -> Self

Creates context for a field that occupies zero bytes on the wire.

pub const fn is_present(&self) -> bool

Returns whether the contextual field is present on the wire.

Trait Implementations

impl Clone for Context

fn clone(&self) -> Context

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Context

impl Debug for Context

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

Formats the value using the given formatter.

impl Eq for Context

impl Hash for Context

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 PartialEq for Context

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Context