Struct rustc_middle::mir::UserTypeProjections

pub struct UserTypeProjections {
    pub contents: Vec<(UserTypeProjection, Span)>,
}

A collection of projections into user types.

They are projections because a binding can occur a part of a parent pattern that has been ascribed a type.

Its a collection because there can be multiple type ascriptions on the path from the root of the pattern down to the binding itself.

An example:

struct S<'a>((i32, &'a str), String);
let S((_, w): (i32, &'static str), _): S = ...;
//    ------  ^^^^^^^^^^^^^^^^^^^ (1)
//  ---------------------------------  ^ (2)

The highlights labelled (1) show the subpattern (_, w) being ascribed the type (i32, &'static str).

The highlights labelled (2) show the whole pattern being ascribed the type S.

In this example, when we descend to w, we will have built up the following two projected types:

• base: S, projection: (base.0).1
• base: (i32, &'static str), projection: base.1

The first will lead to the constraint w: &'1 str (for some inferred region '1). The second will lead to the constraint w: &'static str.

Fields

contents: Vec<(UserTypeProjection, Span)>

Implementations

impl<'tcx> UserTypeProjections

pub fn none() -> Self

pub fn is_empty(&self) -> bool

pub fn projections_and_spans(
    &self
) -> impl Iterator<Item = &(UserTypeProjection, Span)> + ExactSizeIterator

pub fn projections(
    &self
) -> impl Iterator<Item = &UserTypeProjection> + ExactSizeIterator

pub fn push_projection(self, user_ty: &UserTypeProjection, span: Span) -> Self

fn map_projections(
    self,
    f: impl FnMut(UserTypeProjection) -> UserTypeProjection
) -> Self

pub fn index(self) -> Self

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

pub fn deref(self) -> Self

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

pub fn variant(
    self,
    adt_def: AdtDef<'tcx>,
    variant_index: VariantIdx,
    field: Field
) -> Self

Trait Implementations

impl Clone for UserTypeProjections

fn clone(&self) -> UserTypeProjections

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for UserTypeProjections

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

Formats the value using the given formatter.

impl<'tcx, __D: TyDecoder<'tcx>> Decodable<__D> for UserTypeProjections

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

impl<'tcx, __E: TyEncoder<'tcx>> Encodable<__E> for UserTypeProjections

fn encode(&self, __encoder: &mut __E) -> Result<(), <__E as Encoder>::Error>

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

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

impl<'tcx> TypeFoldable<'tcx> for UserTypeProjections

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

Traverses the type in question, typically by calling try_fold_with on each field/element. This is true even for types of interest such as Ty. This should only be called within TypeFolder methods, when non-custom traversals are desired for types of interest.

fn super_visit_with<__F: TypeVisitor<'tcx>>(
    &self,
    __folder: &mut __F
) -> ControlFlow<__F::BreakTy>

Traverses the type in question, typically by calling visit_with on each field/element. This is true even for types of interest such as Ty. This should only be called within TypeVisitor methods, when non-custom traversals are desired for types of interest.

fn try_fold_with<F: FallibleTypeFolder<'tcx>>(
    self,
    folder: &mut F
) -> Result<Self, F::Error>

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

fn fold_with<F: TypeFolder<'tcx, Error = !>>(self, folder: &mut F) -> Self

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

fn super_fold_with<F: TypeFolder<'tcx, Error = !>>(self, folder: &mut F) -> Self

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

fn visit_with<V: TypeVisitor<'tcx>>(
    &self,
    visitor: &mut V
) -> ControlFlow<V::BreakTy>

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

fn has_vars_bound_at_or_above(&self, binder: DebruijnIndex) -> bool

Returns true if self has any late-bound regions that are either bound by binder or bound by some binder outside of binder. If binder is ty::INNERMOST, this indicates whether there are any late-bound regions that appear free.

fn has_vars_bound_above(&self, binder: DebruijnIndex) -> bool

Returns true if this self has any regions that escape binder (and hence are not bound by it).

fn has_escaping_bound_vars(&self) -> bool

fn has_type_flags(&self, flags: TypeFlags) -> bool

fn has_projections(&self) -> bool

fn has_opaque_types(&self) -> bool

fn references_error(&self) -> bool

fn error_reported(&self) -> Option<ErrorGuaranteed>

fn has_param_types_or_consts(&self) -> bool

fn has_infer_regions(&self) -> bool

fn has_infer_types(&self) -> bool

fn has_infer_types_or_consts(&self) -> bool

fn needs_infer(&self) -> bool

fn has_placeholders(&self) -> bool

fn needs_subst(&self) -> bool

fn has_free_regions(&self) -> bool

“Free” regions in this context means that it has any region that is not (a) erased or (b) late-bound.

fn has_erased_regions(&self) -> bool

fn has_erasable_regions(&self) -> bool

True if there are any un-erased free regions.

fn is_global(&self) -> bool

Indicates whether this value references only ‘global’ generic parameters that are the same regardless of what fn we are in. This is used for caching.

fn has_late_bound_regions(&self) -> bool

True if there are any late-bound regions

fn still_further_specializable(&self) -> bool

Indicates whether this value still has parameters/placeholders/inference variables which could be replaced later, in a way that would change the results of impl specialization.

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: 24 bytes