Struct UserTypeProjection

pub struct UserTypeProjection {
    pub base: UserTypeAnnotationIndex,
    pub projs: Vec<ProjectionKind>,
}

Encodes the effect of a user-supplied type annotation on the subcomponents of a pattern. The effect is determined by applying the given list of projections to some underlying base type. Often, the projection element list projs is empty, in which case this directly encodes a type in base. But in the case of complex patterns with subpatterns and bindings, we want to apply only a part of the type to a variable, in which case the projs vector is used.

Examples:

• let x: T = ... – here, the projs vector is empty.

• let (x, _): T = ... – here, the projs vector would contain field[0] (aka .0), indicating that the type of s is determined by finding the type of the .0 field from T.

Fields

base: UserTypeAnnotationIndex

projs: Vec<ProjectionKind>

Implementations

impl UserTypeProjection

pub(crate) fn index(self) -> Self

pub(crate) fn subslice(self, from: u64, to: u64) -> Self

pub(crate) fn deref(self) -> Self

pub(crate) fn leaf(self, field: FieldIdx) -> Self

pub(crate) fn variant( self, adt_def: AdtDef<'_>, variant_index: VariantIdx, field_index: FieldIdx, ) -> Self

Trait Implementations

impl Clone for UserTypeProjection

fn clone(&self) -> UserTypeProjection

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for UserTypeProjection

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

Formats the value using the given formatter.

impl<__D: TyDecoder> Decodable<__D> for UserTypeProjection

fn decode(__decoder: &mut __D) -> Self

impl<__E: TyEncoder> Encodable<__E> for UserTypeProjection

fn encode(&self, __encoder: &mut __E)

impl Hash for UserTypeProjection

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<'__ctx> HashStable<StableHashingContext<'__ctx>> for UserTypeProjection

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

impl PartialEq for UserTypeProjection

fn eq(&self, other: &UserTypeProjection) -> 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<'tcx> TypeFoldable<TyCtxt<'tcx>> for UserTypeProjection

fn try_fold_with<__F: FallibleTypeFolder<TyCtxt<'tcx>>>( self, __folder: &mut __F, ) -> Result<Self, __F::Error>

The entry point for folding. To fold a value t with a folder f call: t.try_fold_with(f).

fn fold_with<F>(self, folder: &mut F) -> Self

where F: TypeFolder<I>,

A convenient alternative to try_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_fold_with.

impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for UserTypeProjection

fn visit_with<__V: TypeVisitor<TyCtxt<'tcx>>>( &self, __visitor: &mut __V, ) -> __V::Result

The entry point for visiting. To visit a value t with a visitor v call: t.visit_with(v).

impl StructuralPartialEq for UserTypeProjection

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: 32 bytes