Struct UnsupportedMatcherKey 

#[non_exhaustive]
pub struct UnsupportedMatcherKey {
    pub class: String,
    pub draft: DraftVersion,
    pub kind: Option<MatchKind>,
    pub key: MatcherKey,
}

A class rule keyed on something no unit it could claim ever carries.

Returned by Capabilities::admit_class and Capabilities::admit_profile before a session forwards anything, so the rule never arms. The message names the draft and the key, because either alone is unactionable: “keys on track_alias” does not say which session it is dead in, and “draft-19” does not say what to change.

#[non_exhaustive] with public fields: nobody constructs an error, and a later release naming a seventh key must not be a breaking change. Reading the fields from outside the crate stays legal, which is what lets a caller branch on the key rather than parse the message.

Display is hand-written rather than a thiserror attribute, unlike ShapeError: the message has two shapes, because a rule that named no MatchKind was judged against both framed kinds and naming one of them in the refusal would misreport what the rule asked for.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

class: String

The ClassRule::name holding the dead key.

draft: DraftVersion

The draft the session would run as.

kind: Option<MatchKind>

The stream kind the rule was aimed at, or None when it named none and the key is carried by neither framed kind on this draft.

key: MatcherKey

The key that can never match.

Trait Implementations

impl Clone for UnsupportedMatcherKey

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for UnsupportedMatcherKey

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

Formats the value using the given formatter.

impl Display for UnsupportedMatcherKey

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

Formats the value using the given formatter.

impl Eq for UnsupportedMatcherKey

impl Error for UnsupportedMatcherKey

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

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

Provides type-based access to context intended for error reports.

impl From<UnsupportedMatcherKey> for ProxyError

fn from(source: UnsupportedMatcherKey) -> Self

Converts to this type from the input type.

impl PartialEq for UnsupportedMatcherKey

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for UnsupportedMatcherKey