Expand description
Trait Resolution. See the rustc-dev-guide for more information on how this works.
Re-exports§
use std::cmp;🔒use std::hash::Hash;🔒use std::hash::Hash;🔒use std::hash::Hasher;🔒use hir::def_id::LocalDefId;🔒use rustc_hir as hir;🔒use rustc_macros::TypeFoldable;🔒use rustc_macros::TypeVisitable;🔒use rustc_middle::traits::query::NoSolution;🔒use rustc_middle::traits::solve::Certainty;🔒use rustc_middle::ty;🔒use rustc_middle::ty::Ty;🔒use rustc_middle::ty::TyCtxt;🔒use rustc_middle::ty::Upcast;🔒use rustc_span::Span;🔒use thin_vec::ThinVec;🔒pub use self::engine::FromSolverError;pub use self::engine::ScrubbedTraitError;pub use self::engine::TraitEngine;pub use self::engine::TraitErrors;pub(crate) use self::project::UndoLog;🔒pub use self::project::MismatchedProjectionTypes;pub use self::project::Normalized;pub use self::project::NormalizedTerm;pub use self::project::ProjectionCache;pub use self::project::ProjectionCacheEntry;pub use self::project::ProjectionCacheKey;pub use self::project::ProjectionCacheStorage;use crate::infer::InferCtxt;🔒
Modules§
- cache
- Cache for candidate selection.
- engine 🔒
- project 🔒
- Code for projecting associated types out of trait references.
- query
- Experimental types for the trait query interface. The methods
defined in this module are all based on canonicalization,
which makes a canonical query by replacing unbound inference
variables and regions, so that results can be reused more broadly.
The providers for the queries defined here can be found in
rustc_traits. - select
- Candidate selection. See the rustc dev guide for more information on how this works.
- solve
- specialization_
graph - structural_
impls 🔒 - util
Structs§
- Derived
Cause - Derived
Host Cause - Impl
Derived Cause - Impl
Derived Host Cause - Impl
Source User Defined Data - Identifies a particular impl in the source, along with a set of
generic parameters from the impl’s type/lifetime parameters. The
nestedvector corresponds to the nested obligations attached to the impl’s type parameters. - Match
Expression ArmCause - Obligation
- An
Obligationrepresents some trait reference (e.g.,i32: Eq) for which the “impl_source” must be found. The process of finding an “impl_source” is called “resolving” theObligation. This process consists of either identifying animpl(e.g.,impl Eq for i32) that satisfies the obligation, or else finding a bound that is in scope. The eventual result is usually aSelection(defined below). - Obligation
Cause - The reason why we incurred this obligation; used for error reporting.
- Obligation
Cause Code Handle - A compact form of
ObligationCauseCode. - Pattern
Origin Expr - Information about the origin expression of a pattern, relevant to diagnostics. Fields here refer to the scrutinee of a pattern. If the scrutinee isn’t given in the diagnostic, then this won’t exist.
- Signature
Mismatch Data
Enums§
- Assoc
Const Violation - Reasons an associated const might not be dyn compatible.
- Builtin
Impl Source - Codegen
Obligation Error - These are the error cases for
codegen_select_candidate. - DynCompatibility
Violation - DynCompatibility
Violation Solution - Evaluation
Result - The result of trait evaluation. The order is important here as the evaluation of a list is the maximum of the evaluations.
- Impl
Source - Given the successful resolution of an obligation, the
ImplSourceindicates where the impl comes from. - IsConstable
- Whether a value can be extracted into a const. Used for diagnostics around array repeat expressions.
- Method
Violation - Reasons a method might not be dyn-compatible.
- Obligation
Cause Code - Overflow
Error - Indicates that trait evaluation caused overflow and in which pass.
- Selection
Error - Well
Formed Loc - The ‘location’ at which we try to perform HIR-based wf checking.
This information is used to obtain an
hir::Ty, which we can walk in order to obtain precise spans for any ‘nested’ types (e.g.FooinOption<Foo>).
Type Aliases§
- Evaluation
Cache - Obligation
Inspector - A callback that can be provided to
inspect_typeck. Invoked on evaluation of root obligations. - Poly
Trait Obligation - Predicate
Obligation - Predicate
Obligations - Selection
- Selection
Cache - Selection
Result - When performing resolution, it is typically the case that there can be one of three outcomes:
- Trait
Obligation