Function rustc_trait_selection::traits::project::confirm_callable_candidate

fn confirm_callable_candidate<'cx, 'tcx>(
    selcx: &mut SelectionContext<'cx, 'tcx>,
    obligation: &ProjectionTyObligation<'tcx>,
    fn_sig: PolyFnSig<'tcx>,
    flag: TupleArgumentsFlag
) -> Progress<'tcx>