Enum ErrorKind 

#[non_exhaustive]
pub enum ErrorKind {
    Resolve,
    Connect,
    Tls,
    Redirect,
    Timeout(Phase),
    Body,
    Decode,
    Status,
    Unsupported,
    Cancelled,
    Other,
}

The error’s category. Exists so the consumer doesn’t have to classify errors by substring-matching on Display.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Resolve

Connect

Tls

Redirect

Timeout(Phase)

Body

Decode

Status

Unsupported

Cancelled

The capability behind the failed operation was pulled out from under it before it could finish — typically, the runtime is shutting down while the task was still queued (see hclient_rt::Cancelled, returned by Blocking::run, amendment-C5).

A separate variant, not Other: Other is the honest answer for a GENUINELY opaque backend error (the default Transport::to_error, when the backend has nothing to say about the category). Cancellation is the opposite of opacity: it’s a condition known in advance and already typed (Cancelled is not a string or an OS error code, but a concrete type), one that EVERY future consumer of the Blocking capability will hit, not a one-off for a single backend. It must not be mixed with Other, and even less with the category of the failed operation itself (e.g. Resolve for a DNS resolver built on Blocking, see hclient-dns-system) — for the same reason Resolve and Other aren’t mixed with each other: the caller must be able to tell “this attempt failed on its merits” from “this attempt didn’t finish because the runtime is shutting down” without a downcast — just by comparing kind().

Other

Trait Implementations

impl Clone for ErrorKind

fn clone(&self) -> ErrorKind

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ErrorKind

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

Formats the value using the given formatter.

impl Eq for ErrorKind

impl PartialEq for ErrorKind

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ErrorKind