Module dyn_compatibility 

“Dyn-compatibility”¹ refers to the ability for a trait to be converted to a trait object. In general, traits may only be converted to a trait object if certain criteria are met.

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1. Formerly known as “object safety”. ↩

Re-exports

use std::ops::ControlFlow; 🔒

use rustc_attr_ir::lang_items::LangItem; 🔒

use rustc_errors::FatalError; 🔒

use rustc_hir as hir; 🔒

use rustc_hir::def_id::DefId; 🔒

use rustc_middle::query::Providers; 🔒

use rustc_middle::ty; 🔒

use rustc_middle::ty::EarlyBinder; 🔒

use rustc_middle::ty::GenericArgs; 🔒

use rustc_middle::ty::Ty; 🔒

use rustc_middle::ty::TyCtxt; 🔒

use rustc_middle::ty::TypeFoldable; 🔒

use rustc_middle::ty::TypeFolder; 🔒

use rustc_middle::ty::TypeSuperFoldable; 🔒

use rustc_middle::ty::TypeSuperVisitable; 🔒

use rustc_middle::ty::TypeVisitable; 🔒

use rustc_middle::ty::TypeVisitableExt; 🔒

use rustc_middle::ty::TypeVisitor; 🔒

use rustc_middle::ty::TypingMode; 🔒

use rustc_middle::ty::Unnormalized; 🔒

use rustc_middle::ty::Upcast; 🔒

use rustc_middle::ty::elaborate; 🔒

use rustc_span::DUMMY_SP; 🔒

use rustc_span::Span; 🔒

use rustc_span::kw; 🔒

use rustc_span::sym; 🔒

use smallvec::SmallVec; 🔒

use tracing::debug; 🔒

use tracing::instrument; 🔒

use tracing::instrument; 🔒

use super::elaborate; 🔒

use crate::infer::TyCtxtInferExt; 🔒

use crate::traits::query::evaluate_obligation::InferCtxtExt; 🔒

use crate::traits::AssocConstViolation; 🔒

use crate::traits::MethodViolation; 🔒

use crate::traits::Obligation; 🔒

use crate::traits::ObligationCause; 🔒

use crate::traits::normalize_param_env_or_error; 🔒

use crate::traits::util; 🔒

Structs

EraseEscapingBoundRegions 🔒

IllegalRpititVisitor 🔒

IllegalSelfTypeVisitor 🔒

Enums

AllowSelfProjections 🔒

DynCompatibilityViolation

Functions

bounds_reference_self 🔒

clauses_reference_self 🔒

contains_illegal_impl_trait_in_trait 🔒

contains_illegal_self_type_reference 🔒

Check if the given value contains illegal Self references.

dyn_compatibility_violations 🔒

dyn_compatibility_violations_for_assoc_item

dyn_compatibility_violations_for_trait 🔒

generics_require_sized_self 🔒

get_sized_bounds 🔒

hir_ty_lowering_dyn_compatibility_violations

Returns the dyn-compatibility violations that affect HIR ty lowering.

is_dyn_compatible 🔒

is_vtable_safe_method

We say a method is vtable safe if it can be invoked on a trait object. Note that dyn-compatible traits can have some non-vtable-safe methods, so long as they require Self: Sized or otherwise ensure that they cannot be used when Self = Trait.

predicate_references_self 🔒

provide 🔒

receiver_for_self_ty 🔒

Performs a type instantiation to produce the version of receiver_ty when Self = self_ty. For example, for receiver_ty = Rc<Self> and self_ty = Foo, returns Rc<Foo>.

receiver_is_dispatchable 🔒

Checks the method’s receiver (the self argument) can be dispatched on when Self is a trait object. We require that DispatchableFromDyn be implemented for the receiver type in the following way:

sized_trait_bound_spans 🔒

super_clauses_are_unconditionally_const 🔒

Checks for const Trait supertraits. We’re okay with [const] Trait, supertraits since for a non-const instantiation of that trait, the conditionally-const supertrait is also not required to be const.

super_clauses_have_non_lifetime_binders 🔒

trait_has_sized_self 🔒

virtual_call_violations_for_method 🔒

Returns Some(_) if this method cannot be called on a trait object; this does not necessarily imply that the enclosing trait is dyn-incompatible, because the method might have a where clause Self: Sized.