pub trait FactorImpl: Factor<DualDVec64> + Factor<f64> {
// Provided methods
fn residual_func_dual(
&self,
params: &[DVector<DualDVec64>],
) -> DVector<DualDVec64> { ... }
fn residual_func_f64(&self, params: &[DVector<f64>]) -> DVector<f64> { ... }
}