Enum LifetimeRibKind

enum LifetimeRibKind {
    Generics {
        binder: NodeId,
        span: Span,
        kind: LifetimeBinderKind,
    },
    AnonymousCreateParameter {
        binder: NodeId,
        report_in_path: bool,
    },
    Elided(LifetimeRes),
    AnonymousReportError,
    StaticIfNoLifetimeInScope {
        lint_id: NodeId,
        emit_lint: bool,
    },
    ElisionFailure,
    ConstParamTy,
    ConcreteAnonConst(NoConstantGenericsReason),
    Item,
}

Variants

Generics

This rib declares generic parameters. Only for this kind the LifetimeRib::bindings field can be non-empty.

Fields

binder: NodeId

span: Span

kind: LifetimeBinderKind

AnonymousCreateParameter

Create a new anonymous lifetime parameter and reference it.

If report_in_path, report an error when encountering lifetime elision in a path:

struct Foo<'a> { x: &'a () }
async fn foo(x: Foo) {}

Note: the error should not trigger when the elided lifetime is in a pattern or expression-position path:

struct Foo<'a> { x: &'a () }
async fn foo(Foo { x: _ }: Foo<'_>) {}

Fields

binder: NodeId

report_in_path: bool

Elided(LifetimeRes)

Replace all anonymous lifetimes by provided lifetime.

AnonymousReportError

Give a hard error when either & or '_ is written. Used to rule out things like where T: Foo<'_>. Does not imply an error on default object bounds (e.g., Box<dyn Foo>).

StaticIfNoLifetimeInScope

Resolves elided lifetimes to 'static if there are no other lifetimes in scope, otherwise give a warning that the previous behavior of introducing a new early-bound lifetime is a bug and will be removed (if emit_lint is enabled).

Fields

lint_id: NodeId

emit_lint: bool

ElisionFailure

Signal we cannot find which should be the anonymous lifetime.

ConstParamTy

This rib forbids usage of generic parameters inside of const parameter types.

While this is desirable to support eventually, it is difficult to do and so is currently forbidden. See rust-lang/project-const-generics#28 for more info.

ConcreteAnonConst(NoConstantGenericsReason)

Usage of generic parameters is forbidden in various positions for anon consts:

• const arguments when generic_const_exprs is not enabled
• enum discriminant values

This rib emits an error when a lifetime would resolve to a lifetime parameter.

Item

This rib acts as a barrier to forbid reference to lifetimes of a parent item.

Trait Implementations

impl Clone for LifetimeRibKind

fn clone(&self) -> LifetimeRibKind

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for LifetimeRibKind

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

Formats the value using the given formatter.

impl Copy for LifetimeRibKind

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 16 bytes

Size for each variant:

• Generics: 15 bytes
• AnonymousCreateParameter: 7 bytes
• Elided: 15 bytes
• AnonymousReportError: 0 bytes
• StaticIfNoLifetimeInScope: 7 bytes
• ElisionFailure: 0 bytes
• ConstParamTy: 0 bytes
• ConcreteAnonConst: 1 byte
• Item: 0 bytes