Function rustc_trait_selection::traits::util::impl_trait_ref_and_oblig

pub fn impl_trait_ref_and_oblig<'a, 'tcx>(
    selcx: &mut SelectionContext<'a, 'tcx>, 
    param_env: ParamEnv<'tcx>, 
    impl_def_id: DefId, 
    impl_substs: SubstsRef<'tcx>
) -> (TraitRef<'tcx>, impl Iterator<Item = PredicateObligation<'tcx>>)

Instantiate all bound parameters of the impl with the given substs, returning the resulting trait ref and all obligations that arise. The obligations are closed under normalization.