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.