Function rustc_trait_selection::traits::coherence::equate_impl_headers

fn equate_impl_headers<'cx, 'tcx>(
    selcx: &mut SelectionContext<'cx, 'tcx>,
    impl1_header: &ImplHeader<'tcx>,
    impl2_header: &ImplHeader<'tcx>
) -> Option<PredicateObligations<'tcx>>