Module rustc::traits::project

🔬 This is a nightly-only experimental API. (rustc_private)

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Code for projecting associated types out of trait references.

Structs

AssociatedTypeNormalizer	[ Experimental ]
MismatchedProjectionTypes	[ Experimental ]
Normalized	[ Experimental ]
Progress	[ Experimental ]
ProjectionCache	[ Experimental ] The projection cache. Unlike the standard caches, this can include infcx-dependent type variables - therefore, we have to roll the cache back each time we roll a snapshot back, to avoid assumptions on yet-unresolved inference variables. Types with skolemized regions also have to be removed when the respective snapshot ends.
ProjectionCacheKey	[ Experimental ]
ProjectionCacheSnapshot	[ Experimental ]

Enums

ProjectedTy	[ Experimental ]
ProjectionCacheEntry	[ Experimental ]
ProjectionTyCandidate	[ Experimental ]
ProjectionTyCandidateSet	[ Experimental ]
ProjectionTyError	[ Experimental ] When attempting to resolve <T as TraitRef>::Name ...
Reveal	[ Experimental ] Depending on the stage of compilation, we want projection to be more or less conservative.

Functions

assemble_candidates_from_impls	[ Experimental ]
assemble_candidates_from_param_env	[ Experimental ] 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	[ Experimental ]
assemble_candidates_from_trait_def	[ Experimental ] In the case of a nested projection like <::FooT as Bar>::BarT, we may find that the definition of Foo has some clues:
assoc_ty_def	[ Experimental ] Locate the definition of an associated type in the specialization hierarchy, starting from the given impl.
confirm_callable_candidate	[ Experimental ]
confirm_candidate	[ Experimental ]
confirm_closure_candidate	[ Experimental ]
confirm_fn_pointer_candidate	[ Experimental ]
confirm_generator_candidate	[ Experimental ]
confirm_impl_candidate	[ Experimental ]
confirm_object_candidate	[ Experimental ]
confirm_param_env_candidate	[ Experimental ]
confirm_select_candidate	[ Experimental ]
get_paranoid_cache_value_obligation	[ Experimental ] Whenever we give back a cache result for a projection like <T as Trait>::Item ==> X, we always include the obligation to prove that T: Trait (we may also include some other obligations). This may or may not be necessary -- in principle, all the obligations that must be proven to show that T: Trait were also returned when the cache was first populated. But there are some vague concerns, and so we take the precautionary measure of including T: Trait in the result:
normalize	[ Experimental ] Normalizes any associated type projections in value, replacing them with a fully resolved type where possible. The return value combines the normalized result and any additional obligations that were incurred as result.
normalize_projection_type	[ Experimental ] 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	[ Experimental ] 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	[ Experimental ] As normalize, but with a custom depth.
opt_normalize_projection_type	[ Experimental ] 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	[ Experimental ] Evaluates constraints of the form:
project_and_unify_type	[ Experimental ] Evaluates constraints of the form:
project_type	[ Experimental ] Compute the result of a projection type (if we can).
prune_cache_value_obligations	[ Experimental ] If there are unresolved type variables, then we need to include any subobligations that bind them, at least until those type variables are fully resolved.

Type Definitions

NormalizedTy	[ Experimental ]
PolyProjectionObligation	[ Experimental ]
ProjectionObligation	[ Experimental ]
ProjectionTyObligation	[ Experimental ]