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

pub(in mir) 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: &'tcx AdtDef,
    variant_index: VariantIdx,
    field: Field
) -> Self

Trait Implementations

impl Clone for UserTypeProjections

pub fn clone(&self) -> UserTypeProjections

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for UserTypeProjections

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

Formats the value using the given formatter.

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

pub fn decode(__decoder: &mut __D) -> Result<Self, <__D as Decoder>::Error>

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

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

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

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

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

pub fn super_fold_with<__F: TypeFolder<'tcx>>(self, __folder: &mut __F) -> Self

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

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

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

pub 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.

pub 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).

pub fn has_escaping_bound_vars(&self) -> bool

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

pub fn has_projections(&self) -> bool

pub fn has_opaque_types(&self) -> bool

pub fn references_error(&self) -> bool

pub fn has_param_types_or_consts(&self) -> bool

pub fn has_infer_regions(&self) -> bool

pub fn has_infer_types(&self) -> bool

pub fn has_infer_types_or_consts(&self) -> bool

pub fn needs_infer(&self) -> bool

pub fn has_placeholders(&self) -> bool

pub fn needs_subst(&self) -> bool

pub 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.

pub fn has_erased_regions(&self) -> bool

pub fn has_erasable_regions(&self) -> bool

True if there are any un-erased free regions.

pub 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.

pub fn has_late_bound_regions(&self) -> bool

True if there are any late-bound regions

pub 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.