Enum HostnameError 

#[non_exhaustive]
pub enum HostnameError {
    Empty,
    TooLong(usize),
    LabelTooLong {
        label: usize,
        len: usize,
    },
    InvalidLabelStart(char),
    InvalidLabelEnd(char),
    InvalidChar(char),
    EmptyLabel,
}

Available on crate feature net only.

Error type for hostname validation.

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.

Empty

Empty hostname

The provided string is empty. Hostnames must contain at least one character.

TooLong(usize)

Hostname exceeds maximum length of 253 characters

According to RFC 1123, hostnames must not exceed 253 characters. This variant contains the actual length of the provided hostname.

LabelTooLong

Label exceeds maximum length of 63 characters

Each label (segment separated by dots) must not exceed 63 characters. This variant contains the label index and its actual length.

Fields

label: usize

Label index

len: usize

Label length

InvalidLabelStart(char)

Label starts with invalid character

Labels must start with a letter (a-z, A-Z). Hyphens and digits are not allowed as the first character. This variant contains the invalid character.

InvalidLabelEnd(char)

Label ends with invalid character

Labels must end with a letter (a-z, A-Z) or digit (0-9). Hyphens are not allowed as the last character. This variant contains the invalid character.

InvalidChar(char)

Invalid character in hostname

Hostnames can only contain ASCII letters, digits, and hyphens. This variant contains the invalid character.

EmptyLabel

Empty label (consecutive dots or leading/trailing dots)

Consecutive dots (e.g., “example..com”) or leading/trailing dots (e.g., “.example.com” or “example.com.”) are not allowed.

Trait Implementations

impl Clone for HostnameError

fn clone(&self) -> HostnameError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HostnameError

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for HostnameError

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for HostnameError

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

Formats the value using the given formatter.

impl Error for HostnameError

Available on crate feature std only.

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 PartialEq for HostnameError

fn eq(&self, other: &HostnameError) -> 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 Serialize for HostnameError

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for HostnameError

impl Eq for HostnameError

impl StructuralPartialEq for HostnameError