Function rustc_trait_selection::traits::normalize_param_env_or_error

pub fn normalize_param_env_or_error<'tcx>(
    tcx: TyCtxt<'tcx>, 
    region_context: DefId, 
    unnormalized_env: ParamEnv<'tcx>, 
    cause: ObligationCause<'tcx>
) -> ParamEnv<'tcx>

Normalizes the parameter environment, reporting errors if they occur.