Function rustc::middle::traits::upcastUnstable
[-] [+]
[src]
pub fn upcast<'tcx>(tcx: &ctxt<'tcx>, source_trait_ref: PolyTraitRef<'tcx>, target_trait_def_id: DefId) -> Vec<PolyTraitRef<'tcx>>
Cast a trait reference into a reference to one of its super
traits; returns None
if target_trait_def_id
is not a
supertrait.