Enum Variants

pub enum Variants<FieldIdx, VariantIdx>
where
    FieldIdx: Idx,
    VariantIdx: Idx,
{
    Empty,
    Single {
        index: VariantIdx,
    },
    Multiple {
        tag: Scalar,
        tag_encoding: TagEncoding<VariantIdx>,
        tag_field: usize,
        variants: IndexVec<VariantIdx, LayoutData<FieldIdx, VariantIdx>>,
    },
}

Variants

Empty

A type with no valid variants. Must be uninhabited.

Single

Single enum variants, structs/tuples, unions, and all non-ADTs.

Fields

index: VariantIdx

Always 0 for types that cannot have multiple variants.

Multiple

Enum-likes with more than one variant: each variant comes with a discriminant (usually the same as the variant index but the user can assign explicit discriminant values). That discriminant is encoded as a tag on the machine. The layout of each variant is a struct, and they all have space reserved for the tag. For enums, the tag is the sole field of the layout.

Fields

tag: Scalar

tag_encoding: TagEncoding<VariantIdx>

tag_field: usize

variants: IndexVec<VariantIdx, LayoutData<FieldIdx, VariantIdx>>

Trait Implementations

impl<FieldIdx, VariantIdx> Clone for Variants<FieldIdx, VariantIdx>

where FieldIdx: Clone + Idx, VariantIdx: Clone + Idx,

fn clone(&self) -> Variants<FieldIdx, VariantIdx>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<FieldIdx, VariantIdx> Debug for Variants<FieldIdx, VariantIdx>

where FieldIdx: Debug + Idx, VariantIdx: Debug + Idx,

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

Formats the value using the given formatter.

impl<FieldIdx, VariantIdx> Hash for Variants<FieldIdx, VariantIdx>

where FieldIdx: Hash + Idx, VariantIdx: Hash + Idx,

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

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<FieldIdx, VariantIdx, __CTX> HashStable<__CTX> for Variants<FieldIdx, VariantIdx>

where FieldIdx: Idx + HashStable<__CTX>, VariantIdx: Idx + HashStable<__CTX>, __CTX: HashStableContext,

fn hash_stable( &self, __hcx: &mut __CTX, __hasher: &mut StableHasher<SipHasher128>, )

impl<FieldIdx, VariantIdx> PartialEq for Variants<FieldIdx, VariantIdx>

where FieldIdx: PartialEq + Idx, VariantIdx: PartialEq + Idx,

fn eq(&self, other: &Variants<FieldIdx, VariantIdx>) -> 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<FieldIdx, VariantIdx> Eq for Variants<FieldIdx, VariantIdx>

where FieldIdx: Eq + Idx, VariantIdx: Eq + Idx,

impl<FieldIdx, VariantIdx> StructuralPartialEq for Variants<FieldIdx, VariantIdx>

where FieldIdx: Idx, VariantIdx: Idx,

Layout

Note: Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.