Function rustc_hir_analysis::impl_wf_check::min_specialization::check_predicates

fn check_predicates<'tcx>(
    tcx: TyCtxt<'tcx>,
    impl1_def_id: LocalDefId,
    impl1_substs: SubstsRef<'tcx>,
    impl2_node: Node,
    impl2_substs: SubstsRef<'tcx>,
    span: Span
)

Check whether predicates on the specializing impl (impl1) are allowed.

Each predicate P must be:

• global (not reference any parameters)
• T: Tr predicate where Tr is an always-applicable trait
• on the base impl impl2
  • Currently this check is done using syntactic equality, which is conservative but generally sufficient.
• a well-formed predicate of a type argument of the trait being implemented, including the Self-type.