fn map_batches_mut<F: FnMut(&mut <Self as TraceReader>::Batch)>(&mut self, mut f: F) {
        for batch in self.merging.iter_mut().rev() {
            match batch {
                MergeState::Double(MergeVariant::InProgress(_batch1, _batch2, _)) => {
                    panic!("map_batches_mut called on an in-progress batch")
                }
                MergeState::Double(MergeVariant::Complete(Some(batch))) => f(batch),
                MergeState::Single(Some(batch)) => f(batch),
                _ => {}
            }
        }
    }
/// Mutate all batches.  Can only be invoked when there are no in-progress
/// matches in the trait.
Mutate all batches.  Can only be invoked when there are no in-progress
matches in the trait.
Mutate all batches . Can only be invoked when there are no in - progress matches in the trait .
fn map_batches_mut<F: FnMut(&mut <Self as TraceReader>::Batch)>(&mut self, mut f: F) {
        for batch in self.merging.iter_mut().rev() {
            match batch {
                MergeState::Double(MergeVariant::InProgress(_batch1, _batch2, _)) => {
                    panic!("map_batches_mut called on an in-progress batch")
                }
                MergeState::Double(MergeVariant::Complete(Some(batch))) => f(batch),
                MergeState::Single(Some(batch)) => f(batch),
                _ => {}
            }
        }
    }
fn map_batches_mut < F : FnMut ( & mut < Self as TraceReader > :: Batch ) > ( & mut self , mut f : F ) { for batch in self . merging . iter_mut ( ) . rev ( ) { match batch { MergeState :: Double ( MergeVariant :: InProgress ( _batch1 , _batch2 , _ ) ) => { panic ! ( " " ) } MergeState :: Double ( MergeVariant :: Complete ( Some ( batch ) ) ) => f ( batch ) , MergeState :: Single ( Some ( batch ) ) => f ( batch ) , _ => { } } } }
Mutate all batches.
Mutate all batches .
&mut self
f
F