Struct rustc_middle::ty::VariantDef

pub struct VariantDef {
    pub def_id: DefId,
    pub ctor_def_id: Option<DefId>,
    pub ident: Ident,
    pub discr: VariantDiscr,
    pub fields: Vec<FieldDef>,
    pub ctor_kind: CtorKind,
    flags: VariantFlags,
}

Definition of a variant – a struct’s fields or a enum variant.

Fields

def_id: DefId

DefId that identifies the variant itself. If this variant belongs to a struct or union, then this is a copy of its DefId.

ctor_def_id: Option<DefId>

DefId that identifies the variant’s constructor. If this variant is a struct variant, then this is None.

ident: Ident

Variant or struct name.

discr: VariantDiscr

Discriminant of this variant.

fields: Vec<FieldDef>

Fields of this variant.

ctor_kind: CtorKind

Type of constructor of variant.

flags: VariantFlags

Flags of the variant (e.g. is field list non-exhaustive)?

Implementations

impl<'tcx> VariantDef

pub fn uninhabited_from(
    &self,
    tcx: TyCtxt<'tcx>,
    substs: SubstsRef<'tcx>,
    adt_kind: AdtKind,
    param_env: ParamEnv<'tcx>
) -> DefIdForest

Calculates the forest of DefIds from which this variant is visibly uninhabited.

impl VariantDef

pub fn new(
    ident: Ident,
    variant_did: Option<DefId>,
    ctor_def_id: Option<DefId>,
    discr: VariantDiscr,
    fields: Vec<FieldDef>,
    ctor_kind: CtorKind,
    adt_kind: AdtKind,
    parent_did: DefId,
    recovered: bool,
    is_field_list_non_exhaustive: bool
) -> Self

Creates a new VariantDef.

variant_did is the DefId that identifies the enum variant (if this VariantDef represents an enum variant).

ctor_did is the DefId that identifies the constructor of unit or tuple-variants/structs. If this is a struct-variant then this should be None.

parent_did is the DefId of the AdtDef representing the enum or struct that owns this variant. It is used for checking if a struct has #[non_exhaustive] w/out having to go through the redirect of checking the ctor’s attributes - but compiling a small crate requires loading the AdtDefs for all the structs in the universe (e.g., coherence for any built-in trait), and we do not want to load attributes twice.

If someone speeds up attribute loading to not be a performance concern, they can remove this hack and use the constructor DefId everywhere.

pub fn is_field_list_non_exhaustive(&self) -> bool

Is this field list non-exhaustive?

pub fn is_recovered(&self) -> bool

Was this variant obtained as part of recovering from a syntactic error?

Trait Implementations

impl Debug for VariantDef

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

Formats the value using the given formatter.

impl<'__ctx> HashStable<StableHashingContext<'__ctx>> for VariantDef

fn hash_stable(
    &self,
    __hcx: &mut StableHashingContext<'__ctx>,
    __hasher: &mut StableHasher
)