fn implied_outlives_bounds<'a, 'tcx>(
infcx: &'a InferCtxt<'tcx>,
param_env: ParamEnv<'tcx>,
body_id: LocalDefId,
ty: Ty<'tcx>,
compat: bool,
) -> Vec<OutlivesBound<'tcx>>
Expand description
Implied bounds are region relationships that we deduce automatically. The idea is that (e.g.) a caller must check that a function’s argument types are well-formed immediately before calling that fn, and hence the callee can assume that its argument types are well-formed. This may imply certain relationships between generic parameters. For example:
fn foo<T>(x: &T) {}
can only be called with a 'a
and T
such that &'a T
is WF.
For &'a T
to be WF, T: 'a
must hold. So we can assume T: 'a
.
§Parameters
param_env
, the where-clauses in scopebody_id
, the body-id to use when normalizing assoc types. Note that this may cause outlives obligations to be injected into the inference context with this body-id.ty
, the type that we are supposed to assume is WF.