Enum Error

pub enum Error {
    Parse(String),
    NamesDontMatch(Ident, Ident),
    MultipleSingularValues(Ident),
    MultipleLiteralValues(Ident),
    SingularAttrRequired(Ident),
    ParametrizedAttrRequired(Ident),
    ArgMustBePath,
    ArgNameRequired,
    ArgNameMustBeIdent,
    ArgNameMustBeUnique(Ident),
    ArgValueRequired(Ident),
    ArgValueMustBeLiteral,
    ArgValueMustBeType,
    ParametrizedAttrHasNoValue(Ident),
    NamedArgRequired(String),
    NestedListsNotSupported(Ident),
}

Errors representing inconsistency in proc macro attribute structure

Variants

Parse(String)

NamesDontMatch(Ident, Ident)

Names of two merged attributes must match each other

MultipleSingularValues(Ident)

Singular argument (of form #[attr = ...]) has multiple occurrences each assigned value. This is meaningless.

MultipleLiteralValues(Ident)

Multiple literal non-string values are given for a parametrized attribute in form of #[attr(literal1, literal2)]. This is meaningless.

SingularAttrRequired(Ident)

Attribute must be in a singular form (#[attr] or #[attr = ...])

ParametrizedAttrRequired(Ident)

Attribute must be in a parametrized form (#[attr(...)])

ArgMustBePath

Attribute argument must be a path identifier like #[attr(std::io)] or #[attr = std::io]

ArgNameRequired

Attribute or attribute argument must has a name

ArgNameMustBeIdent

Attribute or attribute argument name (in form of #[attr(arg = ...)]) must be an identifier (like arg) and not a path (like std::io)

ArgNameMustBeUnique(Ident)

The same argument name is used multiple times within parametrized attribute (like in #[attr(name1 = value1, name1 = value2)])

ArgValueRequired(Ident)

Attribute or attribute argument must has a value: #[attr(arg = value)]

ArgValueMustBeLiteral

Parametrized attribute argument must have a literal value (string, integer etc): #[attr(arg = "value")] or #[arg = 4]

ArgValueMustBeType

Parametrized attribute argument must be a valid type name: #[attr(arg = u8)] or #[arg = String]

ParametrizedAttrHasNoValue(Ident)

Parametrized attribute (in form of #[attr(...)]) does not have a single value

NamedArgRequired(String)

Attribute named argument must be present

NestedListsNotSupported(Ident)

Lists nested within attribute arguments, like #[attr(arg(...))] are not supported

Trait Implementations

impl Clone for Error

fn clone(&self) -> Error

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Error

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

Formats the value using the given formatter.

impl Display for Error

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

Formats the value using the given formatter.

impl Error for Error

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<Error> for Error

fn from(err: Error) -> Self

Converts to this type from the input type.

impl Hash for Error

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 PartialEq for Error

fn eq(&self, other: &Error) -> 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 Eq for Error

impl StructuralPartialEq for Error