Module solve 

The next-generation trait solver, currently still WIP.

As a user of rust, you can use -Znext-solver to enable the new trait solver.

As a developer of rustc, you shouldn’t be using the new trait solver without asking the trait-system-refactor-initiative, but it can be enabled with InferCtxtBuilder::with_next_trait_solver. This will ensure that trait solving using that inference context will be routed to the new trait solver.

For a high-level overview of how this solver works, check out the relevant section of the rustc-dev-guide.

Modules

inspect

Structs

EvalCtxt

ExternalConstraintsData

Additional constraints returned on success.

Goal

A goal is a statement, i.e. predicate, we want to prove given some assumptions, i.e. param_env.

GoalEvaluation

The result of evaluating a goal.

GoalStalledOn

The conditions that must change for a goal to warrant

NestedNormalizationGoals

NoSolution

QueryInput

Response

Enums

AdtDestructorKind

Indicates that a impl Drop for Adt is const or not.

BuiltinImplSource

CandidateSource

Possible ways the given goal can be proven.

Certainty

GenerateProofTree

GoalSource

Why a specific goal has to be proven.

HasChanged

Whether evaluating this goal ended up changing the inference state.

MaybeCause

Why we failed to evaluate a goal.

OpaqueTypesJank

Supporting not-yet-defined opaque types in HIR typeck is somewhat challenging. Ideally we’d normalize them to a new inference variable and just defer type inference which relies on the opaque until we’ve constrained the hidden type.

ParamEnvSource

SizedTraitKind

Which sizedness trait - Sized, MetaSized? PointeeSized is omitted as it is removed during lowering.

Traits

SolverDelegateEvalExt

Functions

evaluate_root_goal_for_proof_tree_raw_provider

Do not call this directly, use the tcx query instead.

Type Aliases

CanonicalInput

CanonicalResponse

QueryResult

The result of evaluating a canonical query.