Struct BoundVarContext

struct BoundVarContext<'a, 'tcx> {
    tcx: TyCtxt<'tcx>,
    map: &'a mut NamedVarMap,
    scope: &'a Scope<'a>,
}

Fields

tcx: TyCtxt<'tcx>

map: &'a mut NamedVarMap

scope: &'a Scope<'a>

Implementations

impl<'a, 'tcx> BoundVarContext<'a, 'tcx>

fn poly_trait_ref_binder_info( &mut self, ) -> (Vec<BoundVariableKind>, BinderScopeType)

Returns the binders in scope and the type of Binder that should be created for a poly trait ref.

fn visit_poly_trait_ref_inner( &mut self, trait_ref: &'tcx PolyTraitRef<'tcx>, non_lifetime_binder_allowed: NonLifetimeBinderAllowed, )

impl<'a, 'tcx> BoundVarContext<'a, 'tcx>

fn with<F>(&mut self, wrap_scope: Scope<'_>, f: F)

where F: for<'b> FnOnce(&mut BoundVarContext<'b, 'tcx>),

fn record_late_bound_vars( &mut self, hir_id: HirId, binder: Vec<BoundVariableKind>, )

fn visit_early_late<F>( &mut self, hir_id: HirId, generics: &'tcx Generics<'tcx>, walk: F, )

where F: for<'b, 'c> FnOnce(&'b mut BoundVarContext<'c, 'tcx>),

Visits self by adding a scope and handling recursive walk over the contents with walk.

Handles visiting fns and methods. These are a bit complicated because we must distinguish early- vs late-bound lifetime parameters. We do this by checking which lifetimes appear within type bounds; those are early bound lifetimes, and the rest are late bound.

For example:

fn foo<’a,’b,’c,T:Trait<’b>>(…)

Here 'a and 'c are late bound but 'b is early bound. Note that early- and late-bound lifetimes may be interspersed together.

If early bound lifetimes are present, we separate them into their own list (and likewise for late bound). They will be numbered sequentially, starting from the lowest index that is already in scope (for a fn item, that will be 0, but for a method it might not be). Late bound lifetimes are resolved by name and associated with a binder ID (binder_id), so the ordering is not important there.

fn visit_early<F>( &mut self, hir_id: HirId, generics: &'tcx Generics<'tcx>, walk: F, )

where F: for<'b, 'c> FnOnce(&'b mut BoundVarContext<'c, 'tcx>),

fn resolve_lifetime_ref( &mut self, region_def_id: LocalDefId, lifetime_ref: &'tcx Lifetime, )

fn check_lifetime_is_capturable( &self, opaque_def_id: LocalDefId, lifetime: ResolvedArg, capture_span: Span, ) -> Result<(), ErrorGuaranteed>

Check for predicates like impl for<'a> Trait<impl OtherTrait<'a>> and ban them. Type variables instantiated inside binders aren’t well-supported at the moment, so this doesn’t work. In the future, this should be fixed and this error should be removed.

fn remap_opaque_captures( &self, opaque_capture_scopes: &Vec<(LocalDefId, &RefCell<FxIndexMap<ResolvedArg, LocalDefId>>)>, lifetime: ResolvedArg, ident: Ident, ) -> ResolvedArg

fn resolve_type_ref(&mut self, param_def_id: LocalDefId, hir_id: HirId)

fn visit_segment_args( &mut self, res: Res, depth: usize, generic_args: &'tcx GenericArgs<'tcx>, )

fn supertrait_hrtb_vars( tcx: TyCtxt<'tcx>, def_id: DefId, assoc_name: Ident, assoc_kind: AssocKind, ) -> Option<(Vec<BoundVariableKind>, &'tcx AssocItem)>

Returns all the late-bound vars that come into scope from supertrait HRTBs, based on the associated type name and starting trait. For example, imagine we have

trait Foo<'a, 'b> {
  type As;
}
trait Bar<'b>: for<'a> Foo<'a, 'b> {}
trait Bar: for<'b> Bar<'b> {}

In this case, if we wanted to the supertrait HRTB lifetimes for As on the starting trait Bar, we would return Some(['b, 'a]).

fn visit_fn_like_elision( &mut self, inputs: &'tcx [Ty<'tcx>], output: Option<&'tcx Ty<'tcx>>, in_closure: bool, )

fn resolve_object_lifetime_default(&mut self, lifetime_ref: &'tcx Lifetime)

fn insert_lifetime(&mut self, lifetime_ref: &'tcx Lifetime, def: ResolvedArg)

fn try_append_return_type_notation_params( &mut self, hir_id: HirId, hir_ty: &'tcx Ty<'tcx>, )

fn for_each_trait_bound_on_res( &self, expected_res: Res, ) -> impl Iterator<Item = DefId> + use<'tcx, '_>

Walk the generics of the item for a trait bound whose self type corresponds to the expected res, and return the trait def id.

Trait Implementations

impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx>

fn visit_opaque_ty(&mut self, opaque: &'tcx OpaqueTy<'tcx>)

Resolve the lifetimes inside the opaque type, and save them into opaque_captured_lifetimes.

This method has special handling for opaques that capture all lifetimes, like async desugaring.

type NestedFilter = OnlyBodies

Override this type to control which nested HIR are visited; see NestedFilter for details. If you override this type, you must also override nested_visit_map.

fn nested_visit_map(&mut self) -> Self::Map

If type NestedFilter is set to visit nested items, this method must also be overridden to provide a map to retrieve nested items.

fn visit_nested_body(&mut self, body: BodyId)

Invoked to visit the body of a function, method or closure. Like visit_nested_item, does nothing by default unless you override Self::NestedFilter.

fn visit_expr(&mut self, e: &'tcx Expr<'tcx>)

fn visit_item(&mut self, item: &'tcx Item<'tcx>)

Visits the top-level item and (optionally) nested items / impl items. See visit_nested_item for details.

fn visit_precise_capturing_arg( &mut self, arg: &'tcx PreciseCapturingArg<'tcx>, ) -> Self::Result

fn visit_foreign_item(&mut self, item: &'tcx ForeignItem<'tcx>)

fn visit_ty(&mut self, ty: &'tcx Ty<'tcx>)

fn visit_pattern_type_pattern(&mut self, p: &'tcx Pat<'tcx>)

fn visit_trait_item(&mut self, trait_item: &'tcx TraitItem<'tcx>)

fn visit_impl_item(&mut self, impl_item: &'tcx ImplItem<'tcx>)

fn visit_lifetime(&mut self, lifetime_ref: &'tcx Lifetime)

fn visit_path(&mut self, path: &Path<'tcx>, hir_id: HirId)

fn visit_fn( &mut self, fk: FnKind<'tcx>, fd: &'tcx FnDecl<'tcx>, body_id: BodyId, _: Span, def_id: LocalDefId, )

fn visit_generics(&mut self, generics: &'tcx Generics<'tcx>)

fn visit_where_predicate(&mut self, predicate: &'tcx WherePredicate<'tcx>)

fn visit_poly_trait_ref(&mut self, trait_ref: &'tcx PolyTraitRef<'tcx>)

fn visit_anon_const(&mut self, c: &'tcx AnonConst)

fn visit_generic_param(&mut self, p: &'tcx GenericParam<'tcx>)

type Map = <Self::NestedFilter as NestedFilter<'v>>::Map

type Result = ()

The result type of the visit_* methods. Can be either (), or ControlFlow<T>.

fn visit_nested_item(&mut self, id: ItemId) -> Self::Result

Invoked when a nested item is encountered. By default, when Self::NestedFilter is nested_filter::None, this method does nothing. You probably don’t want to override this method – instead, override Self::NestedFilter or use the “shallow” or “deep” visit patterns described at rustc_hir::intravisit. The only reason to override this method is if you want a nested pattern but cannot supply a Map; see nested_visit_map for advice.

fn visit_nested_trait_item(&mut self, id: TraitItemId) -> Self::Result

Like visit_nested_item(), but for trait items. See visit_nested_item() for advice on when to override this method.

fn visit_nested_impl_item(&mut self, id: ImplItemId) -> Self::Result

Like visit_nested_item(), but for impl items. See visit_nested_item() for advice on when to override this method.

fn visit_nested_foreign_item(&mut self, id: ForeignItemId) -> Self::Result

Like visit_nested_item(), but for foreign items. See visit_nested_item() for advice on when to override this method.

fn visit_param(&mut self, param: &'v Param<'v>) -> Self::Result

fn visit_body(&mut self, b: &Body<'v>) -> Self::Result

fn visit_id(&mut self, _hir_id: HirId) -> Self::Result

fn visit_name(&mut self, _name: Symbol) -> Self::Result

fn visit_ident(&mut self, ident: Ident) -> Self::Result

fn visit_mod(&mut self, m: &'v Mod<'v>, _s: Span, n: HirId) -> Self::Result

fn visit_local(&mut self, l: &'v LetStmt<'v>) -> Self::Result

fn visit_block(&mut self, b: &'v Block<'v>) -> Self::Result

fn visit_stmt(&mut self, s: &'v Stmt<'v>) -> Self::Result

fn visit_arm(&mut self, a: &'v Arm<'v>) -> Self::Result

fn visit_pat(&mut self, p: &'v Pat<'v>) -> Self::Result

fn visit_pat_field(&mut self, f: &'v PatField<'v>) -> Self::Result

fn visit_inline_const(&mut self, c: &'v ConstBlock) -> Self::Result

fn visit_const_arg(&mut self, c: &'v ConstArg<'v>) -> Self::Result

fn visit_expr_field(&mut self, field: &'v ExprField<'v>) -> Self::Result

fn visit_const_param_default( &mut self, _param: HirId, ct: &'v ConstArg<'v>, ) -> Self::Result

fn visit_fn_ret_ty(&mut self, ret_ty: &'v FnRetTy<'v>) -> Self::Result

fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>) -> Self::Result

fn visit_use( &mut self, path: &'v Path<'v, SmallVec<[Res; 3]>>, hir_id: HirId, ) -> Self::Result

fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) -> Self::Result

fn visit_foreign_item_ref(&mut self, ii: &'v ForeignItemRef) -> Self::Result

fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef) -> Self::Result

fn visit_trait_ref(&mut self, t: &'v TraitRef<'v>) -> Self::Result

fn visit_param_bound(&mut self, bounds: &'v GenericBound<'v>) -> Self::Result

fn visit_variant_data(&mut self, s: &'v VariantData<'v>) -> Self::Result

fn visit_field_def(&mut self, s: &'v FieldDef<'v>) -> Self::Result

fn visit_enum_def( &mut self, enum_definition: &'v EnumDef<'v>, item_id: HirId, ) -> Self::Result

fn visit_variant(&mut self, v: &'v Variant<'v>) -> Self::Result

fn visit_label(&mut self, label: &'v Label) -> Self::Result

fn visit_infer(&mut self, inf: &'v InferArg) -> Self::Result

fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg<'v>) -> Self::Result

fn visit_qpath( &mut self, qpath: &'v QPath<'v>, id: HirId, _span: Span, ) -> Self::Result

fn visit_path_segment( &mut self, path_segment: &'v PathSegment<'v>, ) -> Self::Result

fn visit_generic_args( &mut self, generic_args: &'v GenericArgs<'v>, ) -> Self::Result

fn visit_assoc_item_constraint( &mut self, constraint: &'v AssocItemConstraint<'v>, ) -> Self::Result

fn visit_attribute(&mut self, _attr: &'v Attribute) -> Self::Result

fn visit_associated_item_kind( &mut self, kind: &'v AssocItemKind, ) -> Self::Result

fn visit_defaultness(&mut self, defaultness: &'v Defaultness) -> Self::Result

fn visit_inline_asm( &mut self, asm: &'v InlineAsm<'v>, id: HirId, ) -> Self::Result

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