Struct rustc_trait_selection::error_reporting::infer::need_type_info::FindInferSourceVisitor
source · struct FindInferSourceVisitor<'a, 'tcx> {
tecx: &'a TypeErrCtxt<'a, 'tcx>,
typeck_results: &'a TypeckResults<'tcx>,
target: GenericArg<'tcx>,
attempt: usize,
infer_source_cost: usize,
infer_source: Option<InferSource<'tcx>>,
}
Expand description
A visitor which searches for the “best” spot to use in the inference error.
For this it walks over the hir body and tries to check all places where inference variables could be bound.
While doing so, the currently best spot is stored in infer_source
.
For details on how we rank spots, see Self::source_cost
Fields§
§tecx: &'a TypeErrCtxt<'a, 'tcx>
§typeck_results: &'a TypeckResults<'tcx>
§target: GenericArg<'tcx>
§attempt: usize
§infer_source_cost: usize
§infer_source: Option<InferSource<'tcx>>
Implementations§
source§impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx>
impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx>
fn new( tecx: &'a TypeErrCtxt<'a, 'tcx>, typeck_results: &'a TypeckResults<'tcx>, target: GenericArg<'tcx>, ) -> Self
sourcefn source_cost(&self, source: &InferSource<'tcx>) -> usize
fn source_cost(&self, source: &InferSource<'tcx>) -> usize
Computes cost for the given source.
Sources with a small cost are prefer and should result in a clearer and idiomatic suggestion.
sourcefn update_infer_source(&mut self, new_source: InferSource<'tcx>)
fn update_infer_source(&mut self, new_source: InferSource<'tcx>)
Uses fn source_cost
to determine whether this inference source is preferable to
previous sources. We generally prefer earlier sources.
fn node_args_opt(&self, hir_id: HirId) -> Option<GenericArgsRef<'tcx>>
fn opt_node_type(&self, hir_id: HirId) -> Option<Ty<'tcx>>
fn generic_arg_is_target(&self, arg: GenericArg<'tcx>) -> bool
sourcefn generic_arg_contains_target(&self, arg: GenericArg<'tcx>) -> bool
fn generic_arg_contains_target(&self, arg: GenericArg<'tcx>) -> bool
Does this generic argument contain our target inference variable in a way which can be written by the user.
fn expr_inferred_arg_iter( &self, expr: &'tcx Expr<'tcx>, ) -> Box<dyn Iterator<Item = InsertableGenericArgs<'tcx>> + 'a>
fn resolved_path_inferred_arg_iter( &self, path: &'tcx Path<'tcx>, args: GenericArgsRef<'tcx>, ) -> impl Iterator<Item = InsertableGenericArgs<'tcx>> + 'a
fn path_inferred_arg_iter( &self, hir_id: HirId, args: GenericArgsRef<'tcx>, qpath: &'tcx QPath<'tcx>, ) -> Box<dyn Iterator<Item = InsertableGenericArgs<'tcx>> + 'a>
Trait Implementations§
source§impl<'a, 'tcx> Visitor<'tcx> for FindInferSourceVisitor<'a, 'tcx>
impl<'a, 'tcx> Visitor<'tcx> for FindInferSourceVisitor<'a, 'tcx>
source§fn visit_body(&mut self, body: &Body<'tcx>)
fn visit_body(&mut self, body: &Body<'tcx>)
For closures, we first visit the parameters and then the content, as we prefer those.
source§type NestedFilter = OnlyBodies
type NestedFilter = OnlyBodies
NestedFilter
for details. If you override this type, you
must also override nested_visit_map
. Read moresource§fn nested_visit_map(&mut self) -> Self::Map
fn nested_visit_map(&mut self) -> Self::Map
type NestedFilter
is set to visit nested items, this method
must also be overridden to provide a map to retrieve nested items.fn visit_local(&mut self, local: &'tcx LetStmt<'tcx>)
fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>)
type Map = <Self::NestedFilter as NestedFilter<'v>>::Map
source§fn visit_nested_item(&mut self, id: ItemId) -> Self::Result
fn visit_nested_item(&mut self, id: ItemId) -> Self::Result
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.source§fn visit_nested_trait_item(&mut self, id: TraitItemId) -> Self::Result
fn visit_nested_trait_item(&mut self, id: TraitItemId) -> Self::Result
visit_nested_item()
, but for trait items. See
visit_nested_item()
for advice on when to override this
method.source§fn visit_nested_impl_item(&mut self, id: ImplItemId) -> Self::Result
fn visit_nested_impl_item(&mut self, id: ImplItemId) -> Self::Result
visit_nested_item()
, but for impl items. See
visit_nested_item()
for advice on when to override this
method.source§fn visit_nested_foreign_item(&mut self, id: ForeignItemId) -> Self::Result
fn visit_nested_foreign_item(&mut self, id: ForeignItemId) -> Self::Result
visit_nested_item()
, but for foreign items. See
visit_nested_item()
for advice on when to override this
method.source§fn visit_nested_body(&mut self, id: BodyId) -> Self::Result
fn visit_nested_body(&mut self, id: BodyId) -> Self::Result
visit_nested_item
, does nothing by default unless you override
Self::NestedFilter
.fn visit_param(&mut self, param: &'v Param<'v>) -> Self::Result
source§fn visit_item(&mut self, i: &'v Item<'v>) -> Self::Result
fn visit_item(&mut self, i: &'v Item<'v>) -> Self::Result
visit_nested_item
for details.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_foreign_item(&mut self, i: &'v ForeignItem<'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_array_length(&mut self, len: &'v ArrayLen<'v>) -> Self::Result
fn visit_anon_const(&mut self, c: &'v AnonConst) -> 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_ty(&mut self, t: &'v Ty<'v>) -> Self::Result
fn visit_pattern_type_pattern(&mut self, _p: &'v Pat<'v>)
fn visit_generic_param(&mut self, p: &'v GenericParam<'v>) -> Self::Result
fn visit_const_param_default( &mut self, _param: HirId, ct: &'v ConstArg<'v>, ) -> Self::Result
fn visit_generics(&mut self, g: &'v Generics<'v>) -> Self::Result
fn visit_where_predicate( &mut self, predicate: &'v WherePredicate<'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_fn( &mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, _: Span, id: LocalDefId, ) -> Self::Result
fn visit_use( &mut self, path: &'v Path<'v, SmallVec<[Res; 3]>>, hir_id: HirId, ) -> Self::Result
fn visit_trait_item(&mut self, ti: &'v TraitItem<'v>) -> Self::Result
fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) -> Self::Result
fn visit_impl_item(&mut self, ii: &'v ImplItem<'v>) -> 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_precise_capturing_arg( &mut self, arg: &'v PreciseCapturingArg<'v>, ) -> Self::Result
fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef<'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_lifetime(&mut self, lifetime: &'v Lifetime) -> Self::Result
fn visit_qpath( &mut self, qpath: &'v QPath<'v>, id: HirId, _span: Span, ) -> Self::Result
fn visit_path(&mut self, path: &Path<'v>, _id: HirId) -> 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
Auto Trait Implementations§
impl<'a, 'tcx> !DynSend for FindInferSourceVisitor<'a, 'tcx>
impl<'a, 'tcx> !DynSync for FindInferSourceVisitor<'a, 'tcx>
impl<'a, 'tcx> Freeze for FindInferSourceVisitor<'a, 'tcx>
impl<'a, 'tcx> !RefUnwindSafe for FindInferSourceVisitor<'a, 'tcx>
impl<'a, 'tcx> !Send for FindInferSourceVisitor<'a, 'tcx>
impl<'a, 'tcx> !Sync for FindInferSourceVisitor<'a, 'tcx>
impl<'a, 'tcx> Unpin for FindInferSourceVisitor<'a, 'tcx>
impl<'a, 'tcx> !UnwindSafe for FindInferSourceVisitor<'a, 'tcx>
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
source§impl<T, R> CollectAndApply<T, R> for T
impl<T, R> CollectAndApply<T, R> for T
source§impl<T> Filterable for T
impl<T> Filterable for T
source§fn filterable(
self,
filter_name: &'static str,
) -> RequestFilterDataProvider<T, fn(_: DataRequest<'_>) -> bool>
fn filterable( self, filter_name: &'static str, ) -> RequestFilterDataProvider<T, fn(_: DataRequest<'_>) -> bool>
source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
source§impl<T> IntoEither for T
impl<T> IntoEither for T
source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§impl<P> IntoQueryParam<P> for P
impl<P> IntoQueryParam<P> for P
fn into_query_param(self) -> P
source§impl<T> MaybeResult<T> for T
impl<T> MaybeResult<T> for T
source§impl<T> Pointable for T
impl<T> Pointable for T
source§impl<I, T, U> Upcast<I, U> for Twhere
U: UpcastFrom<I, T>,
impl<I, T, U> Upcast<I, U> for Twhere
U: UpcastFrom<I, T>,
source§impl<I, T> UpcastFrom<I, T> for T
impl<I, T> UpcastFrom<I, T> for T
fn upcast_from(from: T, _tcx: I) -> T
source§impl<Tcx, T> Value<Tcx> for Twhere
Tcx: DepContext,
impl<Tcx, T> Value<Tcx> for Twhere
Tcx: DepContext,
default fn from_cycle_error( tcx: Tcx, cycle_error: &CycleError, _guar: ErrorGuaranteed, ) -> T
source§impl<T> WithSubscriber for T
impl<T> WithSubscriber for T
source§fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
source§fn with_current_subscriber(self) -> WithDispatch<Self>
fn with_current_subscriber(self) -> WithDispatch<Self>
impl<'a, T> Captures<'a> for Twhere
T: ?Sized,
impl<T> ErasedDestructor for Twhere
T: 'static,
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: 104 bytes