@@ -8,10 +8,10 @@ use derive_where::derive_where;
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use rustc_type_ir:: inherent:: * ;
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use rustc_type_ir:: lang_items:: TraitSolverLangItem ;
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use rustc_type_ir:: {
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- self as ty, Interner , TypeFoldable , TypeSuperVisitable , TypeVisitable , TypeVisitableExt as _ ,
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- TypeVisitor , TypingMode , Upcast as _, elaborate,
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+ self as ty, Interner , TypeFoldable , TypeFolder , TypeSuperFoldable , TypeSuperVisitable ,
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+ TypeVisitable , TypeVisitableExt as _ , TypeVisitor , TypingMode , Upcast as _, elaborate,
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} ;
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- use tracing:: { debug , instrument} ;
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+ use tracing:: instrument;
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use super :: trait_goals:: TraitGoalProvenVia ;
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use super :: { has_only_region_constraints, inspect} ;
@@ -367,8 +367,7 @@ where
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} ;
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if normalized_self_ty. is_ty_var ( ) {
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- debug ! ( "self type has been normalized to infer" ) ;
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- return self . forced_ambiguity ( MaybeCause :: Ambiguity ) . into_iter ( ) . collect ( ) ;
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+ return self . try_assemble_bounds_via_registered_opaque ( goal, normalized_self_ty) ;
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}
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let goal: Goal < I , G > =
@@ -873,6 +872,60 @@ where
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}
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}
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+ fn try_assemble_bounds_via_registered_opaque < G : GoalKind < D > > (
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+ & mut self ,
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+ goal : Goal < I , G > ,
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+ self_ty : I :: Ty ,
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+ ) -> Vec < Candidate < I > > {
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+ //println!("for goal {goal:#?} and {self_ty:?}, we found an alias: {:#?}", self.find_sup_as_registered_opaque(self_ty));
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+
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+ let Some ( alias_ty) = self . find_sup_as_registered_opaque ( self_ty) else {
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+ return self . forced_ambiguity ( MaybeCause :: Ambiguity ) . into_iter ( ) . collect ( ) ;
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+ } ;
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+
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+ let mut candidates = vec ! [ ] ;
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+ for item_bound in
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+ self . cx ( ) . item_self_bounds ( alias_ty. def_id ) . iter_instantiated ( self . cx ( ) , alias_ty. args )
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+ {
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+ // TODO: comment
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+ let assumption =
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+ item_bound. fold_with ( & mut ReplaceOpaque { cx : self . cx ( ) , alias_ty, self_ty } ) ;
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+ candidates. extend ( G :: probe_and_match_goal_against_assumption (
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+ self ,
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+ CandidateSource :: AliasBound ,
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+ goal,
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+ assumption,
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+ |ecx| ecx. evaluate_added_goals_and_make_canonical_response ( Certainty :: AMBIGUOUS ) ,
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+ ) ) ;
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+ }
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+
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+ struct ReplaceOpaque < I : Interner > {
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+ cx : I ,
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+ alias_ty : ty:: AliasTy < I > ,
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+ self_ty : I :: Ty ,
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+ }
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+ impl < I : Interner > TypeFolder < I > for ReplaceOpaque < I > {
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+ fn cx ( & self ) -> I {
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+ self . cx
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+ }
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+ fn fold_ty ( & mut self , ty : I :: Ty ) -> I :: Ty {
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+ if let ty:: Alias ( ty:: Opaque , alias_ty) = ty. kind ( ) {
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+ if alias_ty == self . alias_ty {
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+ return self . self_ty ;
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+ }
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+ }
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+ ty. super_fold_with ( self )
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+ }
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+ }
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+
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+ // TODO:
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+ if candidates. is_empty ( ) {
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+ candidates. extend ( self . forced_ambiguity ( MaybeCause :: Ambiguity ) ) ;
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+ }
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+
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+ candidates
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+ }
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+
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/// Assemble and merge candidates for goals which are related to an underlying trait
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/// goal. Right now, this is normalizes-to and host effect goals.
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///
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