Enum StringNewtypeError 

#[non_exhaustive]
pub enum StringNewtypeError {
    Empty,
    Nul,
    Newline,
    Control,
    #[non_exhaustive]
    TooLong {
        len: usize,
        max: usize,
    },
    UnicodeTag,
}

Reasons a string value cannot be promoted into a validated string newtype defined via the crate::string_newtype! macro.

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

The value is empty.

Nul

The value contains a NUL byte.

Newline

The value contains a carriage return or line feed.

Control

The value contains an ASCII control character other than tab.

#[non_exhaustive]

TooLong

The UTF-8 value exceeds STRING_NEWTYPE_MAX_BYTES.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

len: usize

Actual value length in bytes.

max: usize

Maximum accepted value length in bytes.

UnicodeTag

The value contains a Unicode-tag codepoint (U+E0000..U+E007F). These are invisible to humans but readable by some downstream tooling, a known “ASCII smuggling” / log-injection vector. Rejected to keep the type-level “no header injection, ever” contract honest beyond the ASCII-control byte set.

Scope

The Unicode-tag rejection (U+E0000..U+E007F) is scoped to the ASCII-smuggling family only. Other zero-width and visually-confusable codepoints (U+200B..U+200D zero-width spaces, U+2060 word-joiner, U+FEFF BOM, the U+FE00..U+FE0F variation selectors, U+E0100..U+E01EF supplementary variation selectors) are out of scope by design: legitimate text in many scripts (Korean, Hebrew, several CJK renderings) uses them and rejecting them would break valid identifier values. Callers that need a stricter character class should layer their own normalization or rejection on top.

Trait Implementations

impl Clone for StringNewtypeError

fn clone(&self) -> StringNewtypeError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for StringNewtypeError

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

Formats the value using the given formatter.

impl Display for StringNewtypeError

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

Formats the value using the given formatter.

impl Eq for StringNewtypeError

impl Error for StringNewtypeError

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 StringNewtypeError

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for StringNewtypeError