message: FEAT: Add size_hint for StableGraph's node_indices(), edge_indices()
diff: @@ -1362,6 +1362,11 @@ impl<'a, N, Ix: IndexType> Iterator for NodeIndices<'a, N, Ix> {
  } else { None }
  })
  }
  +
  + fn size_hint(&self) -> (usize, Option<usize>) {
  + let (_, hi) = self.iter.size_hint();
  + (0, hi)
  + }
  }
  impl<'a, N, Ix: IndexType> DoubleEndedIterator for NodeIndices<'a, N, Ix> {
  @@ -1403,6 +1408,11 @@ impl<'a, E, Ix: IndexType> Iterator for EdgeIndices<'a, E, Ix> {
  } else { None }
  })
  }
  +
  + fn size_hint(&self) -> (usize, Option<usize>) {
  + let (_, hi) = self.iter.size_hint();
  + (0, hi)
  + }
  }
  impl<'a, E, Ix: IndexType> DoubleEndedIterator for EdgeIndices<'a, E, Ix> {
  