message: added p() and residual() because this is needed by NewtonCG
diff: @@ -81,6 +81,16 @@ where
  base: ArgminBase::new(operator, init_param),
  })
  }
  +
  + /// Return the current search direction (This is needed by NewtonCG for instance)
  + pub fn p(&self) -> T {
  + self.p.clone()
  + }
  +
  + /// Return the current residual (This is needed by NewtonCG for instance)
  + pub fn residual(&self) -> T {
  + self.r.clone()
  + }
  }
  impl<'a, T> ArgminNextIter for ConjugateGradient<'a, T>
  