message: Add CsMatBase::view_mut
diff: @@ -1518,6 +1518,18 @@ where
  }
  })
  }
  +
  + /// Return a mutable view into the current matrix
  + pub fn view_mut(&mut self) -> CsMatViewMutI<N, I, Iptr> {
  + CsMatViewMutI {
  + storage: self.storage,
  + nrows: self.nrows,
  + ncols: self.ncols,
  + indptr: crate::IndPtrView::new_trusted(self.indptr.raw_storage()),
  + indices: &self.indices[..],
  + data: &mut self.data[..],
  + }
  + }
  }
  impl<N, I, Iptr, IptrStorage, IndStorage, DataStorage>
  