Trait HeaderId 

pub trait HeaderId {
    const HEADER_NAME: &'static str;

    // Required method
    fn as_str(&self) -> Cow<'_, str>;
}

A type that is transported as a single HTTP header value.

Implementors provide:

• HEADER_NAME — the canonical header name exactly as it appears in an HTTP request or response, e.g. "X-Request-Id".
• as_str — the string representation of the value, borrowed when the value is already stored as a String, or owned when derived on the fly (e.g. for UUID-backed or structured types).

Generic middleware

The trait enables writing helpers that work uniformly over any header-ID type without duplicating the header-lookup logic:

use api_bones::header_id::HeaderId;

fn log_header<T: HeaderId>(value: &T) {
    println!("{}: {}", T::HEADER_NAME, value.as_str());
}

In axum middleware you can use T::HEADER_NAME to look up the right header for any T: HeaderId + FromStr:

fn extract_header<T>(parts: &axum::http::request::Parts)
    -> Result<T, api_bones::ApiError>
where
    T: HeaderId + core::str::FromStr,
    T::Err: core::fmt::Display,
{
    let raw = parts
        .headers
        .get(T::HEADER_NAME)
        .ok_or_else(|| api_bones::ApiError::bad_request(
            format!("missing required header: {}", T::HEADER_NAME)
        ))?
        .to_str()
        .map_err(|_| api_bones::ApiError::bad_request(
            format!("header {} contains non-UTF-8 bytes", T::HEADER_NAME)
        ))?;
    raw.parse::<T>()
        .map_err(|e| api_bones::ApiError::bad_request(
            format!("invalid {}: {e}", T::HEADER_NAME)
        ))
}

Required Associated Constants

const HEADER_NAME: &'static str

The canonical HTTP header name for this type.

Examples: "X-Request-Id", "X-Correlation-Id", "Idempotency-Key", "traceparent".

Required Methods

fn as_str(&self) -> Cow<'_, str>

Return the string representation of this header value.

Returns a Cow::Borrowed slice when the value is already stored as a String, and a Cow::Owned string when the representation must be computed (e.g. for UUID-backed or structured types).

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl HeaderId for CorrelationId

Available on crate feature std only.

const HEADER_NAME: &'static str = "X-Correlation-Id"

impl HeaderId for IdempotencyKey

Available on crate feature std only.

const HEADER_NAME: &'static str = "Idempotency-Key"

impl HeaderId for OrgId

Available on crate feature std only.

const HEADER_NAME: &'static str = "X-Org-Id"

impl HeaderId for OrgPath

Available on crate feature std only.

const HEADER_NAME: &'static str = "X-Org-Path"

impl HeaderId for RequestId

Available on crate feature std only.

const HEADER_NAME: &'static str = "X-Request-Id"

impl HeaderId for TraceContext

Available on crate feature std only.

const HEADER_NAME: &'static str = "traceparent"