Enum TreatNotYetDefinedOpaques 

pub(crate) enum TreatNotYetDefinedOpaques {
    AsInfer,
    AsRigid,
}

Used by FnCtxt::lookup_method_for_operator with -Znext-solver.

With AsRigid we error on impl Opaque: NotInItemBounds while AsInfer just treats it as ambiguous and succeeds. This is necessary as we want FnCtxt::check_expr_call to treat not-yet-defined opaque types as rigid to support impl Deref<Target = impl FnOnce()> and Box<impl FnOnce()>.

We only want to treat opaque types as rigid if we need to eagerly choose between multiple candidates. We otherwise treat them as ordinary inference variable to avoid rejecting otherwise correct code.

Variants

AsInfer

AsRigid

Trait Implementations

impl Debug for TreatNotYetDefinedOpaques

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.