Struct ErrorResponse 

pub struct ErrorResponse {
    pub error: ErrorCode,
    pub error_description: Option<Cow<'static, str>>,
    pub error_uri: Option<Cow<'static, str>>,
}

The RFC 6749 section 5.2 error response body: error required, error_description and error_uri optional and omitted (never null) when absent.

Why the two optional fields are Cow<'static, str> and not String

This is the type every REFUSAL in this crate is built out of, and a refusal is the one response an attacker chooses the rate of: an unauthenticated caller can ask for as many invalid_request bodies as it can open sockets for, and asks for none of the successful ones. Roughly 50 of the crate’s 57 description sites pass a string constant, so an owned String meant one heap copy of a &'static str per refused request, bought for nothing.

It is free in memory as well as in allocations: Option<Cow<'static, str>> is 24 bytes, the SAME as Option<String>, because Cow’s discriminant lives in the niche the pointer already has. MEASURED, not assumed: ErrorResponse is 56 bytes before and after, and tests/allocation.rs pins both that size and the zero-allocation claim.

A host that needs a description it computed still passes a String: Cow owns that case, and ErrorResponse::with_description takes impl Into<Cow<'static, str>> so both spellings compile unchanged.

Fields

error: ErrorCode

The registered error code.

error_description: Option<Cow<'static, str>>

Human-readable ASCII detail for the developer (not the end user), per section 5.2.

error_uri: Option<Cow<'static, str>>

A URI identifying a human-readable page with more information.

Implementations

impl ErrorResponse

pub fn new(error: ErrorCode) -> Self

A bare error with no description.

pub fn with_description(self, description: impl Into<Cow<'static, str>>) -> Self

Attach a developer-facing description.

impl Into<Cow<'static, str>>, so a &'static str borrows and a String moves: the overwhelmingly common caller passes a literal and pays nothing, and a caller that genuinely computed the text keeps working with no change at the call site.

pub fn with_uri(self, uri: impl Into<Cow<'static, str>>) -> Self

Attach an error_uri (RFC 6749 section 5.2), the same way and for the same reason.

pub fn http_status(&self) -> u16

The HTTP status for this response; see ErrorCode::http_status.

Trait Implementations

impl Clone for ErrorResponse

fn clone(&self) -> ErrorResponse

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ErrorResponse

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ErrorResponse

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for ErrorResponse

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

Formats the value using the given formatter.

impl Eq for ErrorResponse

impl Error for ErrorResponse

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<StepUpFailure> for ErrorResponse

Available on crate feature consent only.

fn from(failure: StepUpFailure) -> ErrorResponse

Converts to this type from the input type.

impl PartialEq for ErrorResponse

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for ErrorResponse

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for ErrorResponse