Module rustc_trait_selection::traits::project

Code for projecting associated types out of trait references.

Structs

• AssocTypeNormalizer 🔒
• BoundVarReplacer
• InProgress 🔒
• PlaceholderReplacer
  The inverse of BoundVarReplacer: replaces placeholders with the bound vars from which they came.
• Progress 🔒

Enums

• ProjectAndUnifyResult 🔒
  States returned from poly_project_and_unify_type. Takes the place of the old return type, which was:
• Projected 🔒
• ProjectionCandidate 🔒
• ProjectionCandidateSet 🔒
• ProjectionError
  When attempting to resolve <T as TraitRef>::Name …
• Reveal
  Depending on the stage of compilation, we want projection to be more or less conservative.

Traits

• NormalizeExt
• ProjectionCacheKeyExt 🔒

Functions

• assemble_candidates_from_impls 🔒
• assemble_candidates_from_object_ty 🔒
  In the case of a trait object like <dyn Iterator<Item = ()> as Iterator>::Item we can use the existential predicate in the trait object.
• assemble_candidates_from_param_env 🔒
  The first thing we have to do is scan through the parameter environment to see whether there are any projection predicates there that can answer this question.
• assemble_candidates_from_predicates 🔒
• assemble_candidates_from_trait_def 🔒
  In the case of a nested projection like <<A as Foo>::FooT as Bar>::BarT, we may find that the definition of Foo has some clues:
• assoc_ty_own_obligations 🔒
• compute_inherent_assoc_ty_args
• confirm_builtin_candidate 🔒
• confirm_callable_candidate 🔒
• confirm_candidate 🔒
• confirm_closure_candidate 🔒
• confirm_fn_pointer_candidate 🔒
• confirm_future_candidate 🔒
• confirm_generator_candidate 🔒
• confirm_impl_candidate 🔒
• confirm_param_env_candidate 🔒
• confirm_select_candidate 🔒
• needs_normalization 🔒
• normalize_inherent_projection
  Confirm and normalize the given inherent projection.
• normalize_projection_type
  The guts of normalize: normalize a specific projection like <T as Trait>::Item. The result is always a type (and possibly additional obligations). If ambiguity arises, which implies that there are unresolved type variables in the projection, we will substitute a fresh type variable $X and generate a new obligation <T as Trait>::Item == $X for later.
• normalize_to_error 🔒
  If we are projecting <T as Trait>::Item, but T: Trait does not hold. In various error cases, we cannot generate a valid normalized projection. Therefore, we create an inference variable return an associated obligation that, when fulfilled, will lead to an error.
• normalize_with_depth 🔒
  As normalize, but with a custom depth.
• normalize_with_depth_to 🔒
• opt_normalize_projection_type 🔒
  The guts of normalize: normalize a specific projection like <T as Trait>::Item. The result is always a type (and possibly additional obligations). Returns None in the case of ambiguity, which indicates that there are unbound type variables.
• poly_project_and_unify_type 🔒
  Evaluates constraints of the form:
• project 🔒
  Computes the result of a projection type (if we can).
• project_and_unify_type 🔒
  Evaluates constraints of the form:
• try_normalize_with_depth_to 🔒
• with_replaced_escaping_bound_vars
  Executes f on value after replacing all escaping bound variables with placeholders and then replaces these placeholders with the original bound variables in the result.

Type Aliases

• PolyProjectionObligation
• ProjectionObligation
• ProjectionTyObligation