Module relate

This module contains the definitions of most TypeRelations in the type system (except for some relations used for diagnostics and heuristics in the compiler). As well as the implementation of Relate for interned things (Ty/Const/etc).

Modules

• combine
• generalize 🔒
• higher_ranked 🔒
  Helper routines for higher-ranked things. See the doc module at the end of the file for details.
• lattice 🔒
  Lattice variables
• solver_relating
• type_relating 🔒

Enums

• StructurallyRelateAliases
  Whether aliases should be related structurally or not. Used to adjust the behavior of generalization and combine.
• VarianceDiagInfo
  Extra information about why we ended up with a particular variance. This is only used to add more information to error messages, and has no effect on soundness. While choosing the ‘wrong’ VarianceDiagInfo may lead to confusing notes in error messages, it will never cause a miscompilation or unsoundness.

Traits

• PredicateEmittingRelation
• Relate
• TypeRelation

Functions

• relate_args_invariantly
• relate_args_with_variances
• structurally_relate_consts
  Relates a and b structurally, calling the relation for all nested values. Any semantic equality, e.g. of unevaluated consts, and inference variables have to be handled by the caller.
• structurally_relate_tys
  Relates a and b structurally, calling the relation for all nested values. Any semantic equality, e.g. of projections, and inference variables have to be handled by the caller.

Type Aliases

• RelateResult