Struct HeaderName 

#[non_exhaustive]
pub struct HeaderName(/* private fields */);

A validated RFC 5322 header field name.

RFC 5322 Section 2.2 defines a field name as 1*ftext, where ftext = %d33-57 / %d59-126 — printable US-ASCII excluding the colon (:). This newtype enforces that constraint at construction time so that downstream code can rely on the name being well-formed.

Case Insensitivity

Comparison and hashing are case-insensitive per RFC 5322 Section 2.2, so HeaderName::new("Subject") and HeaderName::new("subject") are equal.

References

• RFC 5322 Section 2.2 (header field syntax)

Implementations

impl HeaderName

pub fn new(s: impl Into<String>) -> Result<Self>

Creates a new HeaderName after validating ftext syntax (RFC 5322 Section 2.2).

The name must be non-empty and consist solely of printable US-ASCII characters (33..=126) excluding colon (58).

Errors

Returns crate::error::Error::InvalidHeaderName if the name is empty or contains invalid characters.

References

• RFC 5322 Section 2.2

pub fn as_str(&self) -> &str

Returns the header name as a string slice.

pub fn into_inner(self) -> String

Consumes self and returns the inner String.

Trait Implementations

impl AsRef<str> for HeaderName

fn as_ref(&self) -> &str

Converts this type into a shared reference of the (usually inferred) input type.

impl Clone for HeaderName

fn clone(&self) -> HeaderName

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HeaderName

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

Formats the value using the given formatter.

impl Display for HeaderName

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

Displays the header name verbatim (RFC 5322 Section 2.2).

impl From<HeaderName> for String

fn from(h: HeaderName) -> Self

Converts to this type from the input type.

impl Hash for HeaderName

Hash header names case-insensitively so hashing matches equality.

RFC 822 Section 3.4.7: field-name case is not distinguished. RFC 5322 continues the same header field model.

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 Ord for HeaderName

Total ordering on header names, case-insensitive (RFC 5322 Section 2.2).

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for HeaderName

Internet message field names are case-insensitive during comparison.

RFC 822 Section 3.4.7 states this rule explicitly, and RFC 5322 retains the same field-name model for message headers.

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for HeaderName

Order header names case-insensitively (RFC 5322 Section 2.2).

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl TryFrom<&str> for HeaderName

fn try_from(s: &str) -> Result<Self, Self::Error>

Converts a &str into a validated HeaderName (RFC 5322 Section 2.2).

type Error = Error

The type returned in the event of a conversion error.

impl TryFrom<String> for HeaderName

fn try_from(s: String) -> Result<Self, Self::Error>

Converts a String into a validated HeaderName (RFC 5322 Section 2.2).

type Error = Error

The type returned in the event of a conversion error.

impl Eq for HeaderName