Module rustc_middle::traits

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Expand description

Trait Resolution. See the rustc dev guide for more information on how this works.

Re-exports

pub use self::select::EvaluationCache;
pub use self::select::EvaluationResult;
pub use self::select::OverflowError;
pub use self::select::SelectionCache;
pub use self::ObligationCauseCode::*;

Modules

chalk 🔒
Types required for Chalk-related queries
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.
Candidate selection. See the rustc dev guide for more information on how this works.

Structs

A chalk environment and goal.
Identifies a particular impl in the source, along with a set of substitutions from the impl’s type/lifetime parameters. The nested vector corresponds to the nested obligations attached to the impl’s type parameters.
The reason why we incurred this obligation; used for error reporting.

Enums

These are the error cases for codegen_select_candidate.
Given the successful resolution of an obligation, the ImplSource indicates where the impl comes from.
Reasons a method might not be object-safe.
Depending on the stage of compilation, we want projection to be more or less conservative.
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. Foo in Option<Foo>).

Type Definitions

When performing resolution, it is typically the case that there can be one of three outcomes: