Trait SingleAttributeParser

pub(crate) trait SingleAttributeParser<S: Stage>: 'static {
    const PATH: &[Symbol];
    const ATTRIBUTE_ORDER: AttributeOrder;
    const ON_DUPLICATE: OnDuplicate<S>;
    const TEMPLATE: AttributeTemplate;

    // Required method
    fn convert(
        cx: &mut AcceptContext<'_, '_, S>,
        args: &ArgParser<'_>,
    ) -> Option<AttributeKind>;
}

Alternative to AttributeParser that automatically handles state management. A slightly simpler and more restricted way to convert attributes. Assumes that an attribute can only appear a single time on an item, and errors when it sees more.

Single<T> where T: SingleAttributeParser implements AttributeParser.

SingleAttributeParser can only convert attributes one-to-one, and cannot combine multiple attributes together like is necessary for #[stable()] and #[unstable()] for example.

Required Associated Constants

const PATH: &[Symbol]

The single path of the attribute this parser accepts.

If you need the parser to accept more than one path, use AttributeParser instead

const ATTRIBUTE_ORDER: AttributeOrder

Configures the precedence of attributes with the same PATH on a syntax node.

const ON_DUPLICATE: OnDuplicate<S>

Configures what to do when when the same attribute is applied more than once on the same syntax node.

ATTRIBUTE_ORDER specified which one is assumed to be correct, and this specified whether to, for example, warn or error on the other one.

const TEMPLATE: AttributeTemplate

The template this attribute parser should implement. Used for diagnostics.

Required Methods

fn convert( cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>, ) -> Option<AttributeKind>

Converts a single syntactical attribute to a single semantic attribute, or AttributeKind

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<S: Stage> SingleAttributeParser<S> for ExportNameParser

const PATH: &[Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepFirst

const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError

const TEMPLATE: AttributeTemplate

impl<S: Stage> SingleAttributeParser<S> for OptimizeParser

const PATH: &[Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepLast

const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError

const TEMPLATE: AttributeTemplate

impl<S: Stage> SingleAttributeParser<S> for DeprecationParser

const PATH: &[Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepFirst

const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error

const TEMPLATE: AttributeTemplate

impl<S: Stage> SingleAttributeParser<S> for InlineParser

const PATH: &'static [Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepLast

const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError

const TEMPLATE: AttributeTemplate

impl<S: Stage> SingleAttributeParser<S> for RustcForceInlineParser

const PATH: &'static [Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepLast

const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError

const TEMPLATE: AttributeTemplate

impl<S: Stage> SingleAttributeParser<S> for LinkNameParser

const PATH: &[Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepFirst

const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError

const TEMPLATE: AttributeTemplate

impl<S: Stage> SingleAttributeParser<S> for LinkSectionParser

const PATH: &[Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepFirst

const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError

const TEMPLATE: AttributeTemplate

impl<S: Stage> SingleAttributeParser<S> for MustUseParser

const PATH: &[Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepLast

const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError

const TEMPLATE: AttributeTemplate

impl<S: Stage> SingleAttributeParser<S> for PathParser

const PATH: &[Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepLast

const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::WarnButFutureError

const TEMPLATE: AttributeTemplate

impl<S: Stage> SingleAttributeParser<S> for RustcLayoutScalarValidRangeEnd

const PATH: &'static [Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepFirst

const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error

const TEMPLATE: AttributeTemplate

impl<S: Stage> SingleAttributeParser<S> for RustcLayoutScalarValidRangeStart

const PATH: &'static [Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepFirst

const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error

const TEMPLATE: AttributeTemplate

impl<S: Stage> SingleAttributeParser<S> for RustcObjectLifetimeDefaultParser

const PATH: &[Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepFirst

const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error

const TEMPLATE: AttributeTemplate

impl<S: Stage> SingleAttributeParser<S> for IgnoreParser

const PATH: &[Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepLast

const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Warn

const TEMPLATE: AttributeTemplate

impl<S: Stage> SingleAttributeParser<S> for SkipDuringMethodDispatchParser

const PATH: &[Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepFirst

const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error

const TEMPLATE: AttributeTemplate

impl<S: Stage> SingleAttributeParser<S> for TransparencyParser

const PATH: &[Symbol]

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepFirst

const ON_DUPLICATE: OnDuplicate<S>

const TEMPLATE: AttributeTemplate

impl<T: NoArgsAttributeParser<S>, S: Stage> SingleAttributeParser<S> for WithoutArgs<T, S>

const PATH: &[Symbol] = T::PATH

const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepLast

const ON_DUPLICATE: OnDuplicate<S> = T::ON_DUPLICATE

const TEMPLATE: AttributeTemplate